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THE 


ANATOMY  AND  PHYSIOLOGY 


OP 

iB©iDirc 

CONTAINING 

THE  ANATOMY 

OP  THE  BONES,  MUSCLES,  AND  JOINTS,  AND  THE 
HEART  AND  ARTERIES, 

BY  JOHN  BELL ; 

AND 

THE  ANATOMY  AND  PHYSIOLOGY 
OP  THE  BRAIN  AND  NERVES,  THE  ORGANS  OP  THE 
SENSES,  AND  THE  VISCERA, 

BY  CHARLES  BELL,  E.  R.  S.  E. 


SURGEON  TO  THE  MIDDLESEX  HOSPITAL,  AND  READER  »P  ANATOMY 
IN  THE  CHAIR  OP  DR.  HUNTER,  &.C.  &C. 


THE  THIRD  AMERICAN,  FROM  THE  FOURTH  ENGLISH  EDITION. 

IN  THREE  VOLUMES. 

VOL.  I. 

V)  === 


NEW- YORK: 


PRINTED  AND  SOLD  BY  COLLINS  AND  CO.  NO.  189,  PEARL-STREET. 

1817. 


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THE 

ANATOMY 

OF  THE 

HUMAN  BODY. 

VOL.  I. 


CONTAINING 

THE  ANATOMY 

OF 

THE  BONES,  MUSCLES,  AND  JOINTS,  THE  HEART 
AND  CIRCULATION, 

AND 


THE  LUNGS. 


> . 


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I 


TO 


ALEXANDER  WOOD, 

SURGEON, 

WHOSE  ABILITIES  AND  SKILL,  AND  DISINTERESTED 
CONDUCT,  HAVE  RAISED  HIM,  BY 
COM»ION  CONSENT, 

TO  THE  FIRST  RANK,  IN  A MOST  USEFUL 
PROFESSION; 

CONDUCTING  HIM,  IN  HONOUR,  TO  THAT  PERIOD 
OF  LIFE,  IN  WHICH  HE  MUST  FEEL  WITH 
PLEASURE,  HOW  COMPLETELY  HE  ENJOYS  THE 
CONFIDENCE  OF  THE  PUBLIC, 

AND  THE  ESTEEM  OF  ALL  GOOD  MEN, 

THIS  BOOK  OF  ANATOMY, 

IS  PRESENTED, 

BY  HIS  PUPIL, 

JOHN  BELL. 


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PREFACE. 


To  those,  who  are  at  all  acquainted  with  books  on 
anatomy,  the  appearance  of  a new  one  on  the  sub- 
ject will  not  be  surprising.  To  those,  who  are 
not  yet  acquainted  with  such  writings,  I have  only 
to  say,  that  I have  written  this  book,  because  I be- 
lieved that  such  a one  was  needed,  and  must  be  use- 
ful. I have  endeavoured  to  make  it  so  plain  and  sim- 
ple as  to  be  easily  understood ; I have  avoided  the  te- 
dious interlarding  of  technical  terms,  (which  has  been 
too  long  the  pride  of  anatomists,  and  the  disgrace  of 
their  science,)  so  that  it  may  read  smoothly,  com- 
pared with  the  studied  harshness,  and,  I may  say, 
obscurity  of  anatomical  description.  If  an  author 
may  ever  be  allowed  to  compare  his  book  with  others, 
it  must  be  in  the  mechanical  part ; and  I may  ven- 
ture to  say,  that  this  book  is  full  and  correct  in  the 
anatomy,  free  and  general  in  the  explanations,  not 
redundant,  I hope,  and  yet  not  too  brief. 

If,  in  the  course  of,  this  volume,  I shall  appear  to 
have  given  a place  and  importance  to  theories  far 
higher  than  they  really  deserve,  my  reader  uill  natu- 
rally feel  how  useful  they  are  in  preserving  the  due 
balance  between  what  is  amusing,  and  what  is  useful ; 
between  the  looser  doctrines  of  functions,  and  the 
close  demonstration  of  parts.  He  will  be  sensible, 
how  much  more  easily  these  things  can  be  read  in 
the  closet,  than  taught  in  any  public  course  ; he  will, 
I think,  be  ready  to  acknowledge,  that  I introduce 


Vlll 


PREFACE. 


such  theories  only,  as  should  connect  the  whole,  and 
may  be  fairly  chstinguished  as  the  physiology  of 
acts ; and  he  will  perceive,  that  in  this  too,  I feel  a 
deference  for  the  public  opinion,  and  a respect  for  the 
established  course  of  education,  which  it  is  natural 
to  feel  and  to  comply  with. 

Thus,  perhaps  it  is  less  immodest  for  an  author  to 
put  down  what  he  thinks  he  may  honestly  say  con- 
cerning his  own  book,  than  to  omit  those  apologies 
which  custom  requires,  which  give  assurance,  that  he 
has  not  entered  upon  his  task  rashly,  nor  performed 
it  without  some  labour  and  thought,  and  which  are 
the  truest  signs  of  his  respect  for  the  public,  and  of 
his  care  for  that  science  to  which  he  has  devoted  his 
iife. 

With  these  intentions  and  hopes,  I offer  this  book 
to  the  public ; and  more  particularly  to  those  in 
whose  education  I have  a chief  concern ; not  with- 
out a degree  of  satisfaction  at  having  accomplished 
what  I think  cannot  fail  to  be  useful,  and  surely  not 
without  an  apprehension  of  not  having  done  (in  this 
wide  and  difficult  subject)  all  that  may  be  expected 
or  wished  for. 

Every  book  of  this  kind  should  form  a part  of  some 
greater  system  of  education : it  should  not  only  be 
entire  in  its  own  plan,  but  should  be  as  a part  of 
some  greater  whole;  without  which  support  and 
connection,  a book  of  science  is  insulated  and  lost. 
This  relation  and  subserviency  of  his  own  particular 
task  to  some  greater  whole,  is  first  in  an  author’s 
mind  : he  ventures  to  look  forward  to  its  connection 
with  the  general  science,  and  common  course  of 
education;  or  he  turns  it  to  a correspondence  and 
harmony  with  his  own  notions  of  study ; and  if  these 
notions  are  to  give  the  complexion  and  character  to 
any  book,  it  should  be  when  it  is  designed  for  those 
entering  upon  their  studies,  as  yet  uncertain  where  to 
begin,  or  how  to  proceed. 

Hardly  any  one  has  been  so  fortunate  as  to  pursue 
the  study  of  his  own  science  under  any  regular  and 


PREFACE, 


ix 

Jjerfect  plan ; and  there  aie  very  few  with  whom  a 
consciousness  of  this  does  not  make  a deep  and  se- 
rious impression  at  some  future  period,  accompanied 
with  severe  regret  for  the  loss  of  time  never  to 
be  retrieved.  In  medicine,  perhaps,  more  than  in 
any  other  science,  we  begin  our  studies  thoughtless 
and  undecided,  following  whatever  is  delightful,  (as 
much  is  delightful,)  neglecting  the  more  severe  and 
useful  parts  : but  as  we  advance  towards  that  period 
in  which  we  are  to  enter  upon  a most  difficult  profes- 
sion, and  to  take  our  place  and  station  in  life,  and 
when  we  think  of  the  hesitation,  anxiety,  and  appre- 
hension with  which  we  must  move  through  the  first 
years  of  practice,  we  begin  to  look  back  with  regret 
on  every  moment  that  is  past;  with  a consciousness 
of  some  idle  hours ; and  (what  is  more  afflicting  still) 
with  an  unavailing  sense  of  much  ill-directed,  unpro- 
fitable labour : — for  there  is  no  study  Avhich  a young 
man  enters  upon  with  a more  eager  curiosity  ; but, 
not  instructed  in  what  is  really  useful,  nor  seriously 
impressed  with  the  importance  of  his  future  profes- 
sion, he  thinks  of  his  studies  rather  as  the  amusement, 
than  as  the  business,  of  life  ; slumbers  through  his 
more  laborious  and  usefiil  tasks,  and  soon  falls  off  to 
the  vain  pursuit  of  theories  and  doctrines. 

If  I were  not  persuaded  of  the  important  con- 
sequences, of  the  infinite  gain  or  loss,  which  must 
follow  the  first  steps  in  every  profession,  I should 
not  feel,  but,  above  all,  I should  not  venture  to 
show,  an  anxiety,  which  may  be  thought  affected 
by  those  who  cannot  know  how  sincere  it  must  be  ; 
for,  in  our  profession,  this  is  the  course  of  things, 
that  a young  man,  who,  by  his  limited  fortune,  or 
the  will  of  his  friends,  by  absence  fi-om  his  native 
country,  or  by  the  destination  of  his  future  life,  is  re- 
stricted to  a feAV  years  of  irregular,  capricious,  ill-di- 
rected study,  throws  himself  at  once  into  the  practice 
of  a profession,  in  which,  according  to  his  ignorance 
or  skill,  he  must  do  much  good  or  much  harm.  Here 
there  is  no  time  for  his  excursions  into  that  region  of 

b 


X 


PREFACE. 


airy  and  fleeting  visions,  and  for  his  returning  again 
to  sedate  and  useful  labour  : there  is  no  time  for  his 
discovering,  by  the  natural  force  of  his  own  reason, 
how  vain  all  speculations  are  : — in  but  a few  years, 
at  most,  his  education  is  determined ; the  limited 
term  is  completed,  ere  he  have  learnt  that  most  use- 
ful of  all  lessons — the  true  plan  of  study  ; his^oppor- 
' tunities  come  to  be  valued  (like  every  other  happiness) 
only  Avhen  they  are  lost  and  gone. 

Of  all  the  lessons  which  a young  man  entering 
upon  our  profession  needs  to  learn,  this  is,  perhaps, 
the  first, — that  he  should  resist  the  fascinations  of 
doctrines  and  hypotheses,  till  he  have  won  the  privi- 
lege of  such  studies  by  honest  labour,  and  a faithful 
pursuit  of  real  and  useful  knowledge.  Of  this  know- 
ledge, anatomy  surely  forms  the  greatest  share. — 
Anatomy,  even  w^hile  it  is  neglected,  is  universally 
acknowledged  to  be  the  very  basis  of  all  medical 
skill. — It  is  by  anatomy  that  the  physician  gfjesses 
at  the  seat,  or  causes,  or  consequences,  of  any  inter- 
nal disease : without  anatomy,  the  surgeon  could  not 
move  one  step  in  his  great  operations : and  those 
theories  could  not  even  be  conceived,  which  so  often 
usurp  the  place  of  that  very  science,  from  which  they 
should  flow  as  probabilities  and  conjectures  only, 
drawn  from  its  store  of  facts. 

A consciousness  of  the  high  value  of  anatomical 
knowledge  never  entirely  leaves  the  mind  of  the  stu- 
dent. He  begins  with  a strong  conviction  that  this 
is  the  great  study,  and  with  an  ardent  desire  to  mas- 
ter all  its  difficulties  : if  he  relaxes  in  the  pursuit,  it 
is  from  the  difficulties  of  the  task,  and  the  seduction 
of  theories  too  little  dependent  on  anatomy,  and  too 
easily  accessible  without  its  help.  His  desire  for 
real  knowledge  revives,  only  when  the  opportunity  is 
lost ; when  he  is  to  leave  the  schools  of  medicine  ; 
when  he  is  to  give  an  account  of  his  studies,  with  an 
anxious  and  oppressed  mind,  conscious  of  his  igno- 
rance in  that  branch  which  is  to  be  received  as  the 
chief  test  of  his  professional  skill ; or  when,  perhaps. 


PREFACE. 


XI 


he  feels  a more  serious  and  manly  impression,  the 
difficulty  and  importance  of  that  ait  which  he  is 
called  to  practise. 

Yet,  in  spite  of  feeling  and  reason,  the  student  en- 
courages in  himself  a taste  for  speculations  and  theo- 
ries, the  idle  amusements  of  the  day,  which  even  in 
his  own  short  course  of  study,  he  may  observe  sinking 
in  quick  succession  into  neglect  and  oblivion,  never 
to  revive  ; he  aspires  to  the  character  of  a physiolo- 
gist, to  Avhich  want  of  experience  and  a youthful 
fancy,  have  assigned  a rank  and  importance  which  it 
does  not  hold  in  the  estimation  of  those  who  should 
best  know  its  weakness  or  strength.  The  rawest  stu- 
dent, proud  of  his  physiological  knowledge,  boasts  of 
a science  and  a name  which  is  modestly  disclaimed 
by  the  first  anatomist,  and  the  truest  physiologist  of 
this  or  any  age : Dr.  Hunter  speaks  thus  of  his  phy- 
siology, and  of  Iris  anatomical  demonstration  : “ Phy- 
“ siology,  as  fai'  as  it  is  known  or  has  been  explained 
“ by  Haller,  and  the  best  of  the  moderns,  may  be 
“ easily  acquired  by  a student  without  a master,  pro- 
“ vided  the  student  is  acquainted  with  philosophy 
“ and  chemistry,  and  is  an  expert  and  ready  anato- 
“ mist ; for  with  these  qualifications  he  can  read  any 
“ physiological  book,  and  understand  it  as  fast  as  he 
“ reads. 

“ In  this  age,  when  so  much  has  been  printed  up- 
“ on  the  subject,  there  is  almost  as  little  inducement 
“ to  attend  lectures  upon  physiology,  as  there  would 
“ be  for  gentlemen  to  attend  lectures  upon  govern- 
“ ment,  or  upon  the  history  of  England.  Lectures 
“ upon  subjects  which  are  perfectly  intelligible  in 
“ print,  cannot  be  of  much  use,  except  when  given 
“ by  some  man  of  great  abilities,  who  has  laboured 
“ the  subject,  and  who  has  made  considerable  im- 
“ provements  either  in  matter  or  in  arrangement. 

“ In  our  branch,  those  teachers  who  take  but  little 
“ pains  to  demonstrate  the  parts  of  the  body  with 
“ precision  and  clearness,  but  study  to  captivate 
“ young  minds  ^vith  ingenious  speculation,  Avill  not 


PREFACE. 


yii 

“leave  a reputation  that  will  outlive  them  half  a 
“ century. 

“ I always  have  studied,  and  shall  continue  my  en- 
“ deavours,  to  employ  the  time  that  is  given  up  to 
“ anatomical  studies  as  usefully  to  the  students  as  I 
“ can  possibly  make  it — and  therefore  shall  never 
“ aim  at  showing  what  I know,  but  labour  to  show  and 
“ describe,  as  clearly  as  possible,  what  they  ought  to 
“ know.  This  plan  rejects  all  declamation,  all  parade, 
“ all  wrangling,  all  subtilty : to  make  a show,  and 
“ to  appear  learned  and  ingenious  in  natural  know- 
“ ledge,  may  flatter  vanity  ; to  know  facts,  to  sepa- 
“ rate  them  from  suppositions,  to  range  and  connect 
“ them,  to  make  them  plain  to  ordinary  capacities, 
“ and  above  all,  to  point  out  the  useful  applications, 
“ is,  in  my  opinion,  much  more  laudable,  and  shall 

be  the  object  of  my  ambition.”* 

* Introductory  Lecture  published  by  Dr,  Hunter. 


Edinburgh,  Sept.  1793. 


PREFACE 


TO  THE 

FOURTH  EDITION. 


Xn  giving  this  edition  of  the  Anatomy  of  the  Human 
Body  to  the  public,  I have  been  careful  to  revise 
the  descriptions,  and  have  made  some  additions  ; so 
that  I hope  it  will  be  found  to  have  fewer  errors,  and 
to  present  a more  perfect  system. 

Of  the  first  part  of  the  work  by  my  brother,  I may 
speak  more  treely.  And  I may  recommend  it  to 
those  who  superintend  the  education  of  students,  to 
consider  whether  they  have  not  in  it  a work  calcu- 
lated to  open  the  minds  of  the  pupils  to  the  right 
understanding  of  the  important  subjects  of  their 
studies,  and  to  give  them  conect  and  liberal  views  of 
their  profession.  It  will  not  be  soon  surpassed  in 
correctness  and  minuteness  of  description. 

I have  not  dared  to  touch  the  History  of  the  Ar- 
teries ",  the  rapid  improvement  in  the  surgery  of  the 
arteries,  which  followed  as  a consequence  of  the  first 
publication  of  this  part  of  the  Anatomy,  has,  with 
me,  made  it  sacred.  What  is  delivered  on  the  com- 
pression of  the  great  arteries,  is  an  error  on  the  safe 
side.  I may  add,  that  without  the  necessity  of  mak- 
ing experiments  on  so  serious  a subject,  I have 
found  the  strength  of  my  thumb  quite  sufficient  to 
compress  the  main  artery  at  the  groin,  both  in 
wounds  of  the  femoral  artery,  and  in  circumstances 
where  I found  it  necessary  to  amputate  the  thigh, 
without  the  possibility  of  using  the  tourniquet.  I 
must,  however,  acknowledge,  that  I have  seen  too 
much  loss  of  blood  from  trusting  to  compression  in 


XIV 


PREFACE. 


amputating  at  the  shoulder-joint.  I think,  in  one 
instance,  the  patient  died  from  the  loss  of  blood. 
Few  assistants  have  strength  and  dexterity  to  accom- 
plish the  entire  compression  of  the  artery  in  this 
operation,  and  such  have  been  my  fears  of  haemo- 
rrhage, that  having  had  occasion  to  amputate  at  the 
shoulder-joint,  in  order  to  avoid  that  danger,  I 
thought  myself  obliged  to  deviate  from  the  common 
manner  of  performing  the  operation. 

On  the  subject  of  the  Nerves,  my  reader  will  find 
an  account  of  that  system,  which  I have  delivered 
in  my  Lectures  for  ten  years  past.  That  I have  been 
so  long  of  placing  my  own  particular  views  in  a 
systematic  work,  will  only  prove  my  respect  for  the 
received  opinions : but  the  manner  in  which  so 
many  of  my  professional  brethren  have  allowed  them- 
selves to  be  assailed  by  new  and  fantastic  doctrines, 
showing  little  respect  for  the  old,  makes  me  hesitate 
less  in  substituting  opinions  different  from  those 
hitherto  admitted. 

Considerable  additions  have  been  made  to  the 
Anatomy  and  Physiology  of  the  Viscera. 

CHARLES  BELL. 

Soho-Square,  London, 

Jan.  1816. 


OF 

THE  FIRST  VOLUME. 


ANATOMY 

OF  THE 

BONES,  MUSCLES,  AND  JOINTS. 


BOOK  I. 

OF  THE  BONES. 

CHAP.  I. 

OF  THE  FORMATION  AND  GROWTH  OF  BONES,  1. 

Page 

History  of  the  Doctrines  of  Ossification, 

Phenomena  of  ossification. 

Blood  Vessels  and  Absorbents  of  Bones,  and  Proofs  of 

the  Deposition  and  Re-absorption  of  the  Bony  Matter,  7 
Nerves  of  Bones,  and  Proofs  of  the  Sensibility  of  Bones,  11 


The  Process  of  Ossification  described,  . . 13 

1.  The  various  Forms,  and  numerous  Points  of  Ossi- 

fication, .....  14 

2.  The  Heads  and  Processes  of  Long  Bones. 

3.  The  Cavity  of  Long  Bones,  . . 15 

4.  The  CanceHi. 

5.  The  Marrow. 

6.  The  Lammellae,  or  Bony  Plates. 

7.  The  Holes  of  Bones,  ...  17 

8.  The  Vessels,  . . . .18 

9.  The  Periosteum. 


to 


XVi.  CONTENTS. 

Page 

10.  The  Cartilages,  • ...  20 

The  Callus  and  Regeneration  of  Broksn  Bones,  . 21 

CHAP.  II. 

OF  THE  SKULL  IN  GENERAL,  24. 

Importance  of  the  Anatomy  of  the  Skull,  . . 24 

The  Tables  and  Diploe  of  the  Bones  of  the  Skull. 
Enumeration  and  short  Description  of  the  Bones  of  the 
Cranium,  . . . . • .26 

The  Sutures,  .....  27 

Remarks  on  the  Formation,  Nature,  and  Use  of  Sutures,  29 

CHAP.  HI. 

DESCRIPTION  OF  THE  INDIVIDUAL  BONES  OF 
THE  SKULL,  35. 

Os  Fkontis,  . ....  35 

\ 1.  Superciliary  Ridge,  ...  36 

2.  Artery  and  Nerve. 

3.  Angular  Processes. 

4.  Nasal  Process. 

5.  Frontal  Sinuses. 

6.  Frontal  Ridge  or  Spine. 

7.  Orbitary  Process. 

Os  Parietale,  . . ...  .40 

Os  OcciPiTis,  .....  42 

I.  External  Surface. 

1.  Transverse  Spines. 

2.  Crucial  Spine. 

3.  Posterior  Tuberosity. 

II.  Internal  Surface. 

1.  Greal  Internal  Ridge  and  Tentorium  Ce- 

rebello  Superextensum. 

2.  Hollows  of  the  Occipital  Bone. 

Processes  of  the  Occipital  Bone. 

1.  Cuneiform 

2.  Condyles. 

Holes. 

1.  Foramen  Magnum. 

2.  Hole  for  the  ninth  Pair  of  Nerves. 

3.  Hole  for  the  Cervical  Vein  of  the  Neck. 

4.  Common  hole. 

Os  Temporis,  , , . .,  . 44 

Squamous  part.  . 


CONTENTS.  XVll 

Page 

Petrous  Pai’tj  ....  44 

Processes. 

1.  Zygomatic. 

2.  Styloid. 

3.  Vaginal. 

4.  Mastoid  or  Mamillarj’. 

5.  Auditojy. 

Holes. 

For  the  Ear. 

1.  Meatus  Auditorius  Externus. 

2.  Internus. 

3.  Small  Hole  Receiving  a Branch 

from  the  fifth  Pair  of  Nerves. 

4.  Stylo-Mastoid  Hole. 

5.  Hole  for  the  Eustachian  Tube. 

For  Blood  Vessels. 

1.  For  the  Carotid  Artery. 

2.  For  the  Great  Lateral  Sinus,  call- 

ed the  Common  Hole,  as  formed 
partly  by  the  Temporal,  partly 
by  the  Occipital  Bone. 

3.  Small  Hole  on  the  outside  of  the 

Temporal  Bone. 

Os  CEthmoides,  .....  50 

1.  Cribriform  Plate. 

2.  Crista  Galli. 

3.  Nasal  Plate,  or  Azygous  Process. 

4.  Spongy  Bones. 

5.  Orbitary  Plate,  or  Os  Planum. 

6.  Os  Unguis. 

7.  Cells. 

Os  Sphenoides,  .....  52 

Processes. 

1.  Alae. 

2.  Orbitary  process. 

3.  Spinous  process. 

4.  Styloid  process. 

5.  Pterygoid  processes. 

6.  Azygous  process. 

7.  Clynoid  processes. 

Anterior. 

Posterior. 

Celia  Turcica,  and  its  Cells. 

Holes. 

1.  Foramen  Opticum 
c 


von.  1. 


xvm 


CONTENTS. 


Page 

2.  Foramen  Lacerum  . . 56 


3.  

Rotundum. 

4. 

Ovale. 

5. 

Spinale. 

6.  Pterygoid,  or  Vidian  Hole. 
CHAP  IV. 


BONES  OF  THE  FACE  AND  JAWS,  58. 
Ossa  Nasi,  . . . ' . 

OaSA  MAXILLARIA  SuPERlORA, 

Processes. 

1.  Nasal. 

2.  Orbitary. 

3.  Malar. 

4.  Alveolar. 

' 5.  Palate  process. 

Antrum  Maxiilai’e,  or  Higbmorianum. 

Holes. 

1.  Infra  Orb  itary. 

2.  Foramen  Incisivuin,  or  Anterior  Pala- 

tine Hole. 

3.  Posterior  Palatine  Hole. 

OssA  Palati,  ..... 
Processes. 

1.  Palatal  Plate  or  Process. 

Middle  Palatal  Suture. 

Transverse  Palatal  Suture. 

2.  Pterygoid  Process. 

3.  Nasal  Plate  or  Process. 

4.  Orbitary  Process, 

Palatine  Cells. 

Ossa  Spongiosa  or  Turbinata  Inperiora, 

VOMCH,  . . . . 

Os  Mal^,  . . 

Processes. 

1.  Upper  Orbitary. 

2.  Inferior  Orbitary. 

3.  Maxillary. 

4.  Zygomatic. 

5.  Internal  Orbitary. 

Os  Maxillss  Infkkioris, 

Processes. 

1.  Coronoid. 

2.  Condyloid. 

3.  Alveolar. 


58 

59 


64 


65 

66 
67 


6T 


CONTENTS. 


XIX 


Page 

Holes,  ...  .70 

1.  Large  Hole  on  the  inner  Side  for  the 

Entry  of  the  lower  Maxillary  Nerve 
and  Artery. 

2.  Mental  Hole. 

CHAP.  V. 

OF  THE  BONES  OF  THE  TRUNK  ; OF  THE  SPINE, 
THORAX,  AND  PELVIS,  70. 

I.  Of  the  spine General  View  of  the  Spine its 

Motions and  the  Division  t»f  the  Vertebrie,  70 

General  Description  of  a Vertebra,  . 71 

1.  Body  of  the  Vertebra. 

2.  Articulating,  or  Oblique  Processes. 

6.  Spinous  Processes. 

4.  Transverse  Processes. 


Vertebrse  of  the  Loins,  ...  73 

Vertebrca  of  the  Back,  ...  74 

VertebriB  of  the  Neck,  . . .75 

Atlas,  .....  76 

Dentatus,  . . . .76 

Medullary  Tube  and  the  Passage  of  the  Nerves,  79 
Intervertebral  Substance,  . . 79 

Motions  of  the  Vertebra;,  . . SO 

II.  Ribs  and  Sternum,  . . ..  .81 

i.  Of  the  Ribs. 


General  Description  of  a Rib — Division  of 
the  ribs  into  true  and  false — Form  of  a 
Rib,  and  place  of  the  Intercostal  Artery. 

The  parts  of  the  Rib,  as  the  Head,  Neck 
— Surface  for  articulating  with  the 
Transverse  Process — Nature  of  the 
Joint  and  Motion  of  the  Rib — Angle  of 


Rib,  ....  82* 

Size  and  Length  of  the  Ribs — The  Car- 
tilages of  the  Ribs,  . . 83 

ii.  Of  the  Sternum  and  its  three  parts,  . 84 

III.  Of  the  Pelvis,  ....  86 

i.  Os  Sacrum,  ...  87 

ii.  Os  CoccYGis,  ...  89 

iii.  Ossa  Innominata,  . . 89 


1.  Os  Ilium,  or  Haunch-Bone 

1.  Ala — Spine — Spinous  Process 
es,  anterior  and  posterior — • 


XX 


COIN  TENTS. 


2.  Dorsum — 3.  Costa — 4.  Linea 
Innominata, 

ii.  Os  iscHiDBi,  or  Hip-Bone- 

1.  Body — 2.  Tuber — 3.  Ra- 
mus, - - _ 

iii.  Os  Pubis,  or  Share-Bone 

Body Crest Ramus, 

Recapitulation  of  the  chief  Points  of  the 
Anatomy  of  the  Pelvis, 

Size  of  the  Pelvis  in  Man  and  Woman, 
Remarks  on  the  Separation  of  the  Bones 
of  the  Pubes  during  Labour. 

CHAP.  VI. 

BONES  OF  THE  THIGH,  LEG,  AND  FOOT,  98. 

I.  Femur,  - - - * - 

1.  Body. 

2.  Head. 

3.  Neck. 

4.  Trochanter  major. 

5.  Trochanter  minor. 

6.  Linea  aspera. 

7.  Condyles. 

II.  Tibia, 

1.  Upper  Head. 

2.  Body. 

3.  Lower  Head — Inner  Ankle. 

III.  Fibula,  _ . _ _ _ 

1.  Upper  Head. 

2.  Lower  Head — Outer  Ankle. 

IV.  Rotula,  Patella,  or  Knee-pan, 

V.  Tarsus,  or  Instep,  - - - - 

1.  Astragalus. 

2.  Os  Calcis. 

3.  Os  Naviculare. 

4.  ^ 

5.  V Cuneiforme  Bones. 

6.  ) 

7.  Os  Cuboides. 

VI.  Toes, — Sesamoid  Bones,  - 

VII.  Metatarsus  and  its  five  Bones, 


Page 

90 

91 

92 

93 

94 

95 
98 


102 

104 

105 

106 


109 

110 


CONTENTS. 


XXI 


CHAP.  VII. 


Page 

BONES  OF  THE  SHOULDER,  ARM,  AND  HAND,  111. 


I.  Shoulder. 

i.  Scapula  or  Shoulder-blade,  - 111 

1.  The  flat  Side  of  the  Scapula. 

2.  The  upper  flat  Surface. 

3.  The  Triangular  Form  of  the  Scapu- 

la,— Costa — Basis. 

4.  The  Glenoid,  or  Articulating  Cavity. 

5.  The  Neck. 

6.  The  Spine. 

7.  The  Acromion  Process. 

8.  The  Coracoid  Process. 

ii.  Clavicle,  or  Collar-bone,  - 115 

1.  The  Thoracic  End  and  Joint. 

2.  The  Outer  End,  and  its  Union  with 

the  Scapula. 

II.  Arm. 

Os  Humeri,  - - - - 116 

1.  Head. 

2.  Neck. 

3.  Tuberosities. 

4.  Groove  for  the  Tendon  of  the  Biceps 

Muscle. 

5.  Ridges  leading  to  the  Condyles. 

6.  Condyles. 

7.  Articulating  Surface  for  the  Elbow- 

joint,  and  general  Explanation  of 
the  Joint. 

8.  Hollows  for  the  Olecranon  and  Cord- 

noid  Process  of  the  Ulna. 

III.  Ulna  and  Radius,  ...  - H'8 

I.  Ulna. 

1.  Greater  Sigmoid  Cavity,  formed  by 

1.  Olceranon. 

2.  Coronoid  Process. 

2.  Lesser  Sigmoid  Cavity  for  receiving 

the  Head  of  the  Radius. 

3.  Ridges. 

4.  Lower  Head  of  the  Ulna. 

5.  Styloid  Process  of  the  Ulna. 

II.  Radius, 

I.  Body. 


120 


XXU  CONTENTS. 

Page 

2.  Upper  Head,  - - 120 

3.  Necir. 

4.  Point  for  the  Implantation  of  the  Biceps. 

Flexor  Cubiti. 

5.  Lower  Head. 

IV.  Hand  and  Fingers.  - - . 121 

General  Explanation  of  the  Hand  and  Wrist, 
Carpus,  Metacarpus,  and  Fingers. 

' I.  Carpus  or  Wrist,  - - 122 

1.  Rovv  forming  the  Wrist,  - 123 

1.  Os  Scaphoides. 

2.  Os  Lunare. 

3.  Os  Cuneiforme. 

4.  Os  Pisiforme. 

2.  Row  supporting  the  Metacarpal 


Bones,  - - - 124 

1.  Trapezium. 

2.  Trapezoides. 

3.  Os  Magnum. 

4.  OsUnciforme. 

H.  Metacarpus,  - - . 125 

HI.  Fingers,  - 126 

Of  the  Teeth,  by  Mr.  Charles  Bell,  - - 127 


Description  of  the  Human  Adult  Teeth. 

1.  The  Incisores. 

2.  The  Cuspidati,  or  Canine  Teeth. 

3.  The  Bicuspides. 

4.  The  Molares  or  Grinding  Teeth. 

Of  the  first  Set  of  the  Teeth,  the  Milk,  or  Deciduous 


Teeth,  130 

Of  the  Structure  of  the  Teeth,  - - 131 

Of  the  central  bony  Part  of  the  Teeth,  - 133 

Of  the  Vascularity  and  Constitution  of  the  bony  Part 
of  the  Tooth,  . _ _ _ 134 

Of  the  Formation  and  Growth  of  the  Teeth,  - 138 

Of  the  Growth  of  the  second  Set  of  Teeth,  and  the 
shedding  of  the  first,  - - - 14] 


CONTENTS. 


XXIU 


BOOK  II. 

OF  THE  MUSCLES. 

CHAP.  I. 


MUSCLES  OF  THE  FACE,  EYE,  AND  EAR. 

Page 

I.  Muscles  of  the  Face,  . - - - 145 

1.  Occipito  Frontalis. 

2.  Corrugator  Supercilii,  - _ _ 140 

3.  Orbicularis  Oculi,  or,  Palpebrarum,  - 147 

4.  Levator  Palpebraa  Superioris. 

II.  Muscles  of  the  Nose  and  Mouth,  - - 14S 

5.  Levator  Labii  Superioris,  et  Alse  Nasi. 


7.  Levator  Anguli  Oris,  or,  Levator  Com- 
munis Labiorum,  - . . 149 

S.  Zygomaticus  major. 

9.  — minor. 

10.  Buccinator. 

11.  Depressor  Anguli  Oris,  - - - 150 

12.  Depressor  Labii  Inferioris,  or,  Quadratus 

Gense. 

13.  Orbicularis  Oris,  _ _ _ 151 

14.  Depressor  Labii  Superioris,  et  Alas  Nasi,  152 

15.  Constrictor  Nasi. 

16.  Levator  Men ti. 

III.  Muscles  of  the  External  Ear.  - - 152 

17.  Superior  Auris,  - - - - 153 

18.  Anterior  Auris. 

19.  Posterior  Auris. 

20.  Helicis  major. 

21  Helicis  minor,  - - - - 154 

22.  Tragic  us. 

23.  Antitragicus. 

24.  Trans  versus  Auris. 

IV.  Muscles  of  the  Eye-ball.  - - - 154 

General  Explanation  of  these  Muscles. 

25  Rectus  Superior,  _ _ . 155 

26.  Rectus  Inferior. 

27.  Rectus  Internus. 

28.  Rectus  Externus. 

29.  Obliquus  Superior,  . . _ 150 

30.  Obliquus  Inferior.* 


XXiV 


CONTENTS. 


CHAP.  n. 

MUSCLES  OF  THE  LOWER  JAW,  THROAT,  AND  TONGUE. 

Page 

I,  Muscles  of  the  Lower  Jaw,  - - _ 157 

31.  Temporalis. 

32.  Masseter, 

33.  Pterygoideus  Internus,  or  Major,  - 158 

34.  Pterygoideus  Externus,  or  Minor. 

II.  Muscles  of  the  Throat  and  Tongue. 

Explanation  of  certain  Bones  and  Cartilages  form- 
ing the  Basis  of  the  Throat  and  Tongue,  and  the 
Centre  of  their  Motions. 

1.  Os  Hyoides. — Its  Cornua. — Its  Appen- 
dices or  perpendicular  Processes. 


2.  Larynx,  Trachea,  or  Windpipe,  - - 159 

1.  Scutiform,  or  Thyroid  Cartilage,  - 160 

2.  Cricoid  Cartilage. 

3.  Arytenoid  Cartilages,  and  Riraa  Glottidis 

formed  by  them. 

4.  Epiglottis,  - - - - 161 

Recapitulation  and  View  of  the  Constitution  of 

the  Larynx. 

i.  Muscles  of  the  Throat.  - 161 

1.  Muscles  which  pull  the  Throat  down,  - 162 


34.  Sterno-hyoideus. 

35  Sterno-thyroideus. 

36.  Orno  hyoideus. 

Action  of  these  Muscles. 

2.  Muscles  which  move  the  Throat  upwards. 

37.  Blylo- hyoideus. 

38.  Genio-hyoideus,  - - - 163 

39.  ''tylo-hyoideus. 

40.  Digastricus,  or  Biventer  Maxillae  Inferio- 

ris. 

3.  Muscles  moving  the  Parts  and  Cartilages  of 

the  Larynx  upon  each  other.  - - 164 

41.  Hyo-thyroideus. 

42.  Crico-thyroideus. 

43.  Musculus  Arytenoideus  Transversus,  165 

44.  Musculus  Arytenoideus  Obliquus. 

45.  Crico  Arytenoideus  Posticus. 

46.  Crico  Arytenoideus  Obliquus. 

47.  Thyreo  Arytenoideus. 

4.  Muscles  of  the  Palaje  and  Pharynx. 

48.  Azygos  Uvulae, 


166 


CONTENTS. 


XXV 


Page 

49.  Levator  Palati  Mollis.  - - 166 

50.  Circumfiexus  Palati,  or  Tensor  Palati 

Mollis. 

51.  Constrictor  Isthmi  Fauscium,  - 167 

52.  Palato  Pharyngeus. 

Pharynx  explained. 

53.  Stylo-pbaryngeus,  - - - 168 

54.  Constrictor  Superior. 

55.  Constrictor  Medius. 

56.  Constrictor  Inferior,  - - 169 

57.  (Esophagus. 

58.  Vaginalis  Gulae. 

ii.  Muscles  of  the  Tongue. 

59.  Hyo-glossus. 

60.  Genio-glossus. 

61.  Lingualis. 

Motions  of  the  Tongue  performed  by  these 
Muscles. 

CHAP.  III. 

OF  THE  MUSCLES  OF  THE  ARM,  INCLUDING  THE  MUS- 
CLES OF  THE  SCAPULA,  ARM,  FORE-ARM,  AND  HAND. 

I.  Muscles  of  the  Scapula,  - - 171 

i.  Muscles  moving  the  Scapula  upwards  and 

backwards. 

62.  Trapezius. 

63.  Levator  Scapulae,  or  Levator  Proprius 

Angularis,  - - - 172 

64.  and  65.  Rhomboides. 

1.  Minor,  - - 173 

2.  Major. 

ii.  Muscles  which  move  the  Scapula  downwards 

and  forwards. 


66.  Serratus  Major  Anticus. 

67.  Pectoralis  Minor, 

68.  Subclavius. 

Motions  of  the  Scapula. 

II.  Muscles  moving  the  Os  Humeri, 

OR  Arm-Bone. 

174 

69.  Pectoralis  Major, 

70.  Latissimus  Dorsi. 

• 

- 

175 

71.  Deltoides, 

■ - 

- 

176 

72.  Coraco-brachialis, 

- 

- 

177 

78.  Supra  Spinatus, 
VoL.  I.  d 

- 

178 

XXVI 


CONTENTS. 


74.  Infra  Spinatus,  - - - - J78 

75.  Teres  Minor,  - - _ - 179 

76.  Teres  Major. 

77.  Subscapularis. 

Motions  of  the  Humerus,  and  Use  and  Effect 
of  each  of  these  Muscles  in  forming  and 
strengthening  the  Joint,  - - . JSO 

III.  Muscles  moving  the  Fore- arm. 

i.  Muscles  bending  the  Fore-arm,  - - 181 

78.  Biceps  Brachii  Flexor. 

79.  Brachialis  Internus,  - - _ 192 

ii.  Muscles  extending  the  Fore-arm. 

80.  Triceps  Extensor. 

81.  Anconeus,  _ - - . 184 

IV.  Muscles  situated  on  the  Fore-arm  moving  the 


Radius,  Carpus,  and  Fingers. 

Fascia  of  the  Arm. 

Arrangement  of  these  Muscles,  the  Points  of 
Origin  and  Insertion,  and  the  Motions  of  Pro- 
nation and  Supination,  Flexion  and  Exten- 
sion, explained,  - - - - 185 

i.  Flexors,  arising  from  the  Inner  Condyle,  186 

82.  Pronator  Teres  Radii. 

83.  Palmaris  Longus,  _ - _ 137 

84.  Palmaris  Brevis,  or  Cutaneus,  188 

85.  Flexor  Carpi  Radialis. 

86.  Flexor  Carpi  Ulnaris,  - - 189 

87.  Flexor  Digitorum  Sublimis. 

88.  Flexor  Digitorum  Profundus,  vel  Perfo- 

rans,  _ - - - _ 190 

89.  Lumbricales,  - - - 191 

90.  Flexor  Longus  Pollicis,  - - 192 

91.  Pronator  Quadratus. 

ii.  Extensors  arising  from  the  Outer  Condyle,  193 

92.  Supinator  Radii  Longus. 

93.  Extensor  Carpi  Radialis  Longior,  - 194 

94.  Extensor  Carpi'Radialis  Brevior. 

95.  Extensor  Carpi  Ulnaris,  - - 195 

96.  Extensor  Digitorum  Communis. 

97.  Extensor  Minimi  Digiti,  or  Auricularis,  196 

98.  Extensor  Primus  Pollicis,  ^ - 197 

99.  Extensor  Secundus  Pollicis,  > - 198 

100.  Extensor  Tertius  Pollicis.  J 

101.  Indicator,  . _ _ - 199 

102.  Supinator  Brevis. 


CONTENTS. 

V,  Muscles  seated  on  the  Hand. 

Table  of  these  Muscles, 

103.  Abductor  Pollicis. 

104.  Opponens  Pollicis, 

105.  Flexor  Brevis  Pollicis. 

106.  Adductor  Polliois, 

107.  Abductor  Minimi  Digiti 

108.  Flexor  Parvus  Minimi  Digiti. 

109.  Adductor  Minimi  Digiti, 

110.  Abductor  Indicis. 

111.  Interossei  Interni. 

112.  Interossei  Externi. 

CHAP.  IV. 

MUSCLES  OF  RESPIRATION,  OR  OF  THE  RIBS. 

General  Explanation  and  Table  of  these  Muscles. 

113.  Serratus  Superior  Posticus 

114.  Serratus  Inferior  Posticus. 

115.  Levatores  Costarum, 

116.  Intercostales. 

117.  Triangularis  Sterni,  or,  Stemo-costalis 

CHAP.  V. 

MUSCLES  OF  THE  HEAD,  NECK,  AND  TRUNK. 

I.  Muscles  of  the  Head  and  Neck. 

118.  Splenius. 

119.  Complexus. 

120.  Trachelo  mastoideus. 

121.  Rectus  Minor. 

122.  Rectus  Major. 

123.  Obliquus  Superior,  _ 

124.  Obliquus  Inferior. 

II.  Muscles  of  the  Trunk. 

125.  Quadratus  Lumborum. 

126.  Longissimus  Dorsi, 

127.  Sacro  Lumbalis,  - - - 

128.  Cervicalis  Descendens. 

129.  Transversalis  Colli,  . - 

Arrangement  of  the  intricate  Set  of 
Muscles  filling  up  the  Hollows  and 
Interstices  among  the  Spines  and 
Processes  of  the  Vertebra^, 


xxvii 

Page 

199 

200 

201 

202 

203 


204 

205 

206 

207 

208 

210 

211 

212 

213 

214 


214 


xxvm 


CONTENTS. 


130.  Spinalis  Cervicis,  - - - 315 

131.  Spinalis  Dorsi. 

132  Semi-spinalis  Dorsi,  - - - 216 

133.  Multifidus  Spinie. 

134.  Inter-spinalis  Colli,  Dorsi,  et  Lumborum,  217 

135.  Inter-transversales. 

III.  MrSCl.KS  ON  THK'  FORK  PART  OF  THE  HeAD  AND 

Neck,  completing  the  Catalogue  of  those  belong- 
ing to  the  Spine. 

136.  Platysma  Myoides. 

137.  Mastoideus,  - - _ . 218 

136.  Rectus  Internus  Capitis  Major. 

139.  Rectus  Internus  Capitis  Minor. 

140.  Rectus  Capitis  Lateralis. 

141  Longus  Colli. 

142.  Scaleni,  - - - - 219 

CHAP.  VI. 

OF  THE  MUSCLES  OF  THE  ABDOMEN,  AND  OP  THE 
DIAPHRAGM. 


I.  Muscles  of  the  Abdomen  - _ - 220 

Importance  of  the  Anatomy  of  the  Abdominal 
Muscles,  — General  Explanation  of  these 
Muscles, — their  Uses, — Arrangement. 

143  Obliquus  Externus,  _ _ - 221 

144.  Obliquus  Internus,  - - 222 

145  Transversalis  Abdominis. 

146  Recti,  - - - - 223 

147-  Pyramidalis. 

Explanation  of  the  Lines,  Rings,  &zc.  of  the 
Abdominal  Muscles. 

1 Linea  Alba. 

2.  Linea  Semilunaris,  - - 224 

3.  Sheath  for  the  Rectus. 

4.  Umbilicus. 

5.  Ring  of  the  Abdominal  Muscles,  225 

148.  Cremaster  Muscle  of  the  Testicle,  226 

6.  Ligament  of  the  Thigh, 

Explanation  of  the  different  Kinds  of  Hernia, 

and  the  Points  at  which  the  Bowels  are  pro- 
truded. - - - - 227 

Uses  of  the  Abdominal  Muscles. 


CONTENTS. 


XXIX 


Page 

II.  Diaphbagm,  - 227 

149.  The  Diaphragm. 

1.  The  Greater,  or  Upper  Muscle  of  the 

Diaphragm,  - - - 228 

2.  The  Lesser  Muscle  of  the  Diaphragm. 

3.  The  Tendon  in  the  Centre  of  the  Dia- 

phragm. 

Vessels  perforating  the  Diaphragm,  - 229 

1.  Aorta. 

2.  (Esophagus. 

3.  The  Great  Vena  Cava. 

The  Tendon  of  the  Diaphragm. 

Uses  of  the  Diaphragm,  - - 230 

CHAP.  VII. 

THE  MUSCLES  OF  THE  PARTS  OF  GENERATION,  AND 
OF  THE  ANUS  AND  PERINEUM. 

General  Idea  of  these  Muscles,  - - _ 231 

Structure  of  the  Penis. 

150.  Erector  Penis. 

151.  Transversalis  Perinaei,  - - 232 

152.  Accelerator. 

153.  Sphincter  Ani,  - . . 233 

154.  Levator  Ani. 

155.  Musculus  Coccygseus,  - - 234 

Perinaeum, — the  Point  where  All  these  Muscles  are  united. 
Course  of  the  Incision  in  Lithotomy. 

CHAP.  VIII. 

MUSCLES  OF  THE  THIGH,  LEG,  AND  FOOT. 

I.  Muscles  moving  the  Thigh-bone,  - - 235 

General  Description  of  these  Muscles, — Classifi- 
cation and  Arrangement  of  them, — and  Table 
of  their  Implantations,  and  of  the  Motions  which 
they  perform. 

Fascia  of  the  Thigh,  . _ _ 237 

156.  Musculus  Fascialis,  or.  Tensor  Vaginae  Fe- 

moris,  - - - 238 

157.  Psoas  Magnus. 

158.  Psoas  Parvus. 

159.  Iliacus  Inlernus,  ...  289 

160.  Pectineus,  or  Pectinalis. 


XXX 


CONTENTS. 


Tags 

161.  Triceps  Femoris,  _ - - 240 

1.  Adductor  Longus. 

2.  Adductor  Brevis. 

3.  Adductor  Magnus,  - - 241 

162.  Obturator  Externus. 

163.  Glutfeus  Maximus,  _ - . 242 

164.  Glutaeus  Medius,  or  Minor. 

165.  Glutaeus  Minimus,  . - - 243 

167  I 

168.  Pyriformis. 

169.  Obturator  Internus,  - - - 244 

170.  Quadratus  Femoris. 

Motions  of  the  Thigb,  and  Action  of  these  Muscles. 

>11.  Muscles  of  the  Leg,  - - - 245 

Arrangement  of  these  Muscles. 

i.  Extensors  of  the  Leg. 

171.  Rectus  Femoris,  or,  Rectus  Cruris,  - 246 

172.  Cruraeus,  - 247 

Sub  cruraei,  being  Slips  only  of  the  Cru- 
raeus. 

173.  Vastus  Externus. 

174.  Vastus  Internus. 

Uses  of  these  Muscles,  _ _ - 248 

ii.  Flexors  of  the  Leg,  - - - 249 

175.  Sartorius. 

176.  Gracilis,  or,  Rectus  Internus  Femoris. 

177.  Seraitendinosus,  - - - 250 

178.  Semimembranosus. 

179.  Poplitaeus,  - - - - 251 

180.  Biceps  Cruris. 

III.  Muscles  of  the  Foot,  - - - 252 

Arrangement. 

i.  Extensors. 

181-  Gastrocnemius. 

182.  Soleus,  - - - ■ 253 

183.  Plantaris. 

184-  Peronseus  Longus,  - - - 254 

185.  Peronaeus  Brevis,  - - - 255 

186.  Peronaeus  Tertius. 

187.  Tibialis  Posticus,  _ - - 256 

ii.  Flexor. 

188.  Tibialis  Anticus. 

IV.  Muscles  of  the  Toes,  _ - - 257 


CONTENTS. 


XXXI 


Page 

189.  Flexor  Longus  Pollicis.  - - 257 

190.  Flexor  Longus  Digitorum  Pedis  Perforans,  258 

191.  Massa  Carnea  J.  Silvii,  or,  Plantae  Pedis,  259 

192.  Flexor  Brevis  Digitorum. 

193.  Lumbricales,  - - _ 260 

194.  Extensor  Longus  Digitorum  Pedis. 

195.  Extensor  Digitorum  Brevis,  - - 261 

196.  Extensor  Pollicis  Proprius. 

Crucial  Ligament,  _ - - 262 

197.  Abductor  Pollicis.  ^ 

198.  Flexor  Brevis  Pollicis,  > - - 263 

199.  Adductor  Pollicis.  } 

200.  Transversalis  Pedis. 

201.  Abductor  Mintmi  Digiti. 

202.  Flexor  Brevis  Minimi  Digiti,  - - 264 

203.  Interossei  Interni. 

204.  Interossei  Externi. 

205.  Plantaris  Aponeurosis. 


CHAP.  IX. 

OF  THE  MUSCULAR  POWER,  266 

CHAP.  X. 

OF  THE  TENDONS,  LIGAMENTS,  BURS^,  AND  ALL  THE 
PARTS  WHICH  BELONG  TO  THE  BONES  OR  MUSCLES, 
OR  WHICH  ENTER  INTO  THE  CONSTITUTION  OF  A 
JOINT.  - _ - _ . 277 

General  Explanation  of  the  Tendons,  Ligaments,  &c. 

Of  the  Forms  of  the  Cellular  Substance,  - 278 

1.  Its  Cells,  and  their  Use. 

2.  Bursas  Mucosas. 

3.  Vagin®,  or  Fasciae. 

4.  Tendons. 

5.  Periosteum. 

6.  Vagina,  or  Sheaths  of  Tendons. 

7.  Capsules  of  the  Joints. 

8.  Ligaments  of  Joints. 

Recapitulation  and  Review  of  the  Connections  of  these 
Parts,  _ - - - - - - 282 

Constitution  and  Nature  of  those  less  feeling  Parts 
— almost  insensible  in  Health, — slcw^to  inflame— = 
their  Inflammation  very  violent,  though  slow — Dis- 
eases to  which  they  are  liable. 


xxxn 


CONTENTS. 


BOOK  m. 

OF  THE  JOINTS. 

CHAP.  I. 

Tagt 

JOINTS  OF  THE  HEAD  AND  TRUNK.  286. 

I.  Joints  of  the  Head  and  Spine. 

The  Motions  of  the  Head  and  Spine. 

The  Provisions  of  these  Motions. 

i.  Joint  of  the  Head  with  the  Neck. 

1.  Articulation  of  the  Occiput  and  Atlas. 

Form  of  the  Joint  and  Capsules  for  the 
Condyles. 

2.  Flat  membranous  Ligament  from  the  Ring 

of  the  Atlas  to  the  Ring  of  the  Occipi- 
tal Hole.  - - - 287 

3.  Articulation  of  the  Atlas  with  the  Den- 
tatus. 

Capsules  betwixt  the  Condyles  of  the 
Vertebrse. 

Transverse  Ligament  embracing  the 
Neck  of  the  Tooth-like  Process — Cap- 
sular Ligament. 

Ligament  betwixt  the  Tooth-like  Process 
and  Occipital  Hole. 

ii.  Joints  of  the  Common  Vertebrae  with  each 
other. 

Intervertebral  Substance,  and  Intervertebral 
Ligaments. 

External  or  Anterior  Vagina,  or  Ligament  of 
the  Spine,  - 288 

Internal  Ligaments,  - - _ 289 

Ligamenta  Subflava  Crurum  Processuum 
Spinosorum — Membranae  Interspinales— 
Ligamenta  Processuum  Transversorum. 
Posterior  or  Internal  Ligament  of  the  Spine. 
Apparatus  Ligamentosus  Colli. 

II.  Joint  of  the  Lower  Jaw,  _ - - 290 

III.  Joints  of  the  Ribs,  . - - _ 291 

Ligamenta  Capitelli  Costarum. 

Ligamentum  Transversarium  Externum. 

1 — Internum. 

Capsule  and  Ligaments  belonging  to  the 
Cartilages. 


CONTENTS. 


xxxiii 


CHAP.  II. 

JOINTS  OF  THE  SHOULDER,  ARM,  AND  HAND. 

Page 

I.  Joints  of  the  Clavicle,  _ - > 292 

With  the  Sternum. 

With  the  Scapula. 

II.  Joint  of  the  Shouluek,  » - _ 293 

III.  Joint  of  the  Et.bow,  _ - - - 295 

The  General  Capsule  of  the  whole  Joint. 

The  Lateral  Ligaments,  External  and 
Internal,  - - - - 296 

The  Coronary  Ligament  of  the  Ulna. 

Accessory  Ligaments. 

IV.  Whist,  - 297 

Articulation  of  the  Scaphoid  and  Lunated  Bones 
with  the  Scaphoid  Cavity  of  the  Radius. 

Articulation  of  the  Radius  with  the  Ulna  for  the 
turning  Motions  of  the  Hand,  - - 298 

Articulation  of  the  Bones  of  the  Carpus  with 
each  other. 

Articulations  of  the  Metacarpus. 

V.  Joints  of  the  Fingers,  . - - 299 

CHAP  III. 

JOINTS  OF  THE  THIGH,  LEG,  AND  ANKLE,  300 
I.  The  Hip-Joint. 

The  Ligamentum  Labri  Cartilaginei  Transver- 
sale,  -----  301 

The  Capsule  of  the  Joint. 

The  Internal  Ligaments. 

II.  Knee  Joint,  -----  303 

1.  The  External  Ligaments. 

Capsule — and  Ligamentum  Posticum  Win- 
slowii. 

Lateral  Ligaments,  - - . 304 

Ligamentum  Laterale  Internum. 

Externum  Longior. 

Brevior. 

2.  The  Internal  or  Crucial  Ligaments  of  the 

Knee, 

Posterior  Crucial  Ligament. 

Anterior  . - - 305 

VoL  I. 


e 


xxxiy 


CONTENTS. 


Page 

Semilunar,  or^raoveable  Cartilages.  - 305 

Ligamentum  Mucosum — and  Ligamentura 

Alare  Majus  et  Minus,  ...  306 

Bursae  Mucosa  of  the  Knee  Joint. 

Recapitulation,  explaining  the  Constitution  of 
this  Joint,  and  Uses  of  its  several  Parts,  - 307 

III.  Articulation  of  the  Fibula  with  the  Tibia,  - 308 

IV.  Ankle  Joint,  .....  309 


Ligamentum  Superius  Anticum. 

Posticum. 

Inferius  Posticum. 

Capsule. 

• Ligamentum  Deltoides,  - - 310 

Fibulae  Anterius. 

Perpendiculare. 

Inter  Fibulam  et  Astragalum 

Posterius. 

V.  Joints  of  the  Foot. 

Articulations  of  the  Bones  of  the  Tarsus 
with  each  other. 

Joints  of  the  Metatarsus  and  Toes,  - 311 

Aponeurosis  Plantaris  Pedis. 

Bursaj  Mucosae  of  ihe  Ankle  and  Foot,  - 312 
Conclusion  and  Enumeration  of  the  Joints. 


ANATOMY 

OF  THE 

HEART  AND  ARTERIES. 


BOOK  I. 

OF  THE  HEART. 

CHAP.  I. 

OF  THE  MECHANISM  OF  THE  HEART,  316 

General  View  of  the  Circulating  System,  - - 316 

Of  the  Parts  of  the  Heart, 

Venae  Cavae, 


~ 321 


CONTENTS. 


XXXV 


Page 

Right  Sinus  of  the  Heart,  - - 322 

Tuberculum  Loweri. 

Auricle,  - - - - 323 

Auricular  Valv'es. 

Right  Ventricle,  ...  324 

Pulmonic  Artery,  ...  325 

Sigmoid  Valves,  _ . - _ 326 

Left  Auricle,  ....  327 

Semilunar  Valves  of  the  Aorta,  - - 328 

Aorta. 

Of  the  Coronary  Vessels,  ....  330 

Eustachian  Valve,  _ . . 333 

Irritability  and  Action  of  the  Heart,  - 338 

Posture  of  the  Heart,  ...  343 

Pericardium,  ....  345 

Conclusion,  - 349 

CHAP.  II. 

ON  THE  APPEARANCE  AND  PROPERTIES  OF  THE  BLOOD, 
OF  THE  CHEMISTRY  OF  OUR  FLUIDS,  AND  OF  THE 


INFLUENCE  WHICH  AIR  HAS  UPON  THEM,  355 

History  of  Opinions  concerning  the  Blood. 

Life  of  the  Blood,  .....  301 
Qualities  of  the  Blood,  ....  357 

Of  the  Red  Globules,  ....  303 

Coagulable  Lymph,  ...  371 

Serum,  .....  372 

General  View  of  the  Nature  of  the  Blood. 

Chemistry  of  the  Blood,  ....  373 

Influence  of  Air  upon  the  Blood,  - - - ^ 377 

1.  In  reddening  the  Blood,  ...  331 

2.  In  communicating  its  stimulant  Powers,  - 382 

3.  In  communicating  Heat  to  the  Body.  - 383 

Of  the  Respiration  of  Animals,  ...  334 

Of  the  Membranes  of  Cavities,  and  particularly  of  the 

Membranes  of  the  Thorax,  - . - 330 

Of  the  Pleura,  - . . . . 339 

Of  the  Mediastinum,  ....  391 

Of  the  Pericardium,  ....  394 

Of  the  Thymus  Gland,  ....  395 

Of  the  Lungs. 

1'rachea  and  Bronchi,  ....  390 

Bronchial  Cells,  - - . . . 393 

Course  of  the  Blood  in  the  Lungs,  - - . 399 


\ 


rr-  I6'<r''» 
...V'eJT" 


IPlate  I . 


Plate  H= 


]Plat(E  HI. 


C.  .&/-  rf^L 


.'io. 

' fl 


EXPLANATION 


OF 

THE  PLATES. 

PLATE  I. 

This  plate  illustrates  the  description  of  the  manner  in  which 
ossification  takes  place  in  cartilage. 

Fig.  1. 

The  tibia  of  the  foetus  cut  through  after  injection  of  the  ar- 
teries. 

A.  The  body  of  the  bone,  the  centre  of  which  is  soft  and 
very  vascular. 

BB.  The  CARTILAGES,  which  are  as  yet  in  place  of  the  heads 
of  the  bone. 

cc.  Vessels  seen  to  penetrate  the  cartilage  from  the  vascular 
extremity  of  the  bone  itself. 

D.  A centra]  nucleus  of  bone  forming  in  the  cartilage. 

EE.  Vessels  penetrating  from  perichondrium  into  the  carti- 
lage : small  specks  of  bony  matter  are  seen  to  be  formed 
by  their  extremities. 

Fig.  2 

A section  of  the  bones  forming  the  knee  joint  of  a child,  show- 
ing how  the  apophysis  is  formed. 

A,  Section  of  the  femur,  where  the  bone  is  complete. 

B.  The  cartilaginous  extremity,  as  in  fig.  1. 

c.  A larger  mass  of  bone  formed  in  the  cartilage,  and  which 
extending,  in  a short  time  would  have  occupied  the  place 
of  the  whole  cartilage.  The  tract  of  vessels  supplying 
the  bone,  and  which  were  not  visible  in  the  cartilage,  are 
also  represented  here. 

D.  The  patella,  as  yet  a cartilage. 

E.  The  Upper  extremity  of  the  tibia,  yet  a cartilage. 

F.  The  bone  forming  in  the  cartilage. 


XXXVUl 


EXPLANATION  OP  THE  PLATES. 


FiC.  3. 

Represents  a section  of  the  apophysis  of  a young  bone ; the 
bony  nucleus  separated  from  the  cartilage  by  maceration. 

A.  The  cartilage. 

B.  The  bone. 

Explanation  op  Plate  II. 

Explaining  the  obscure  subject  of  necrosis,  or  death  of  a bone, 
and  regeneration  of  a new  one  in  its  stead. 

Fig.  1. 

The  bone  of  a cock’s  leg  which  was  perforated,  and  a fea- 
ther introduced  into  the  cavity  of  the  bone — the  consequence 
necrosis. 

AA.  The  old  bone  dark  yellow,  and  not  partaking  of  the  in- 
jection, because,  though  retained  in  its  place,  dead, 
c.  The  new  bone  formed  around  the  old  cylinder  of  bone, 
and  uniting  with  the  end  of  the  old  bone. 

B.  The  end  of  the  feather,  which  as  a foreign  body  within  the 
bone,  first  caused  the  bone  to  inflame  and  throw  out  new 
matter,  and  still  continuing  a source  of  irritation,  killed 
the  bone. 

Fig.  2. 

Example  of  the  process  of  necrosis  in  the  human  bone. 
This  is  the  thigh  bone  of  a stump  remaining  after  amputation 
of  the  knee. 

A.  The  old  bone  where  it  was  sawn  through  in  operation. 

B B.  The  old  bone  seen  through  the  interstices  of  the  new 
bone. 

c c.  The  new  bone  inclosing  the  old  shaft. 

D.  The  head  of  the  bone  in  a natural  state. 

The  process  here  was  similar  to  that  in  the  experiment  on 
the  cock.  The  wound  going  v/rong,  a bad  suppuration  comes 
upon  the  stump,  a wasting  discharge  comes  from  within  the 
bone,  the  bone  is  inflamed ; the  disease  of  the  marrow  pro- 
ceeds, the  bone  dies,  but  not  till  new  bone  has  been  formed 
around  the  old. 

During  such  a process  it  is  not  wonderful  that  the  continued 
irritation  destroys  the  patient. 

Fig.  3. 

But  sometimes  it  happens  that  after  these  injuries  are  sus- 


EXPLANATION  OF  THE  PLATES. 


xxxix 


tained,  the  old  bone  comes  away  as  in  this  example ; and  the 
stump  may  yet  do  well. 

Explanation  op  Plate  III. 


This  plate  illustrates  the  chapter  on  the  formation  of  the 
teeth. 


Fig  I. 

A tooth  cut  through  and  burnt. 

A.  The  enamel  not  affected  by  the  heat. 

B.  The  body  of  the  bone  black. 

c.  The  caned  of  the  tooth,  in  which  solely  the  sensible  nerve 
lies. 

Fig.  2. 

Shows  the  saccular  pulp  and  rudiments  of  a tooth. 

A.  The  pulp  of  the  form  of  the  tooth  hanging  out  of  its  proper 

place. 

B.  The  sac  which  contains  the  pulp  and  tooth,  but  being  slit 

open  they  have  fallen  out  of  it. 

c.  The  shell  of  this  bony  part  of  the  tooth  which  was  fojmed 
on  the  pulp  a ; but  being  a secretion  from  it,  and  not  con- 
nected otherways  with  it,  it  has  fallen  off. 


Fig.  3.  and  4. 

The  rudiments  of  a bony  part  of  a tooth,  when  beginning 
to  form  on  the  projecting  parts  of  the  pulp. 

Fig  5. 


A common  example  of  a ball  found  in  the  centre  of  an  ele- 
phant’s tooth. 

A.  A part  of  the  iron  ball  discovered. 

B B.  Bone  formed  in  circles  round  the  tooth, 
c.  The  common  matter  of  the  tooth. 

D.  Lesser  nuclei  of  bone  marking  the  irregular  action  of  se- 
cretion near  the  ball. 

Fig.,  6. 

The  bag  containing  the  tooth  and  pulp,  from  the  human 
subject. 

A.  The  bag,  or  sacculiis. 

B.  The  lower  part  of  the  pulp  when  it  can  be  seen  without 

opening  the  sac. 


xl  EXPLANATION  OP  THE  PLATES. 

c.  The  sac  a contains  the  rudiments  of  the  milk-tooth,  and 
here  appended  is  already  the  rudiments  of  the  second 
tooth.  • 

FIG.  7. 

Section  of  the  jaw  of  a child. 

A.  The  incisores  of  the  first  set  of  teeth. 

B.  c.  D.  £.  The  rudiments  of  the  eye  tooth. 

B.  The  pulp,  having  a connection  with  the  sacculus,  and  re- 
ceiving arteries  from  the  bone. 

G.  The  soft  pulp  within  the  sac,  and  in  situ. 

D.  The  connection  of  the  sacculus  with  the  gum. 

The  bone  of  the  tooth  forming. — And  now  it  will  be  per- 
ceived how  it  increases : how  successive  layers  of  bone  are 
deposited  by  the  pulp  beneath;  and  how  in  due  time  the 
enamel  is  deposited  upon  the  bone  of  the  tooth  by  the  sac 
which  surrounds  it. 


THE 


OF  THE 


BONES,  MUSCLES,  AND  JOINTS. 


BOOK  I. 

OF  THE  BONES. 

■ 

CHAP.  I. 

OP  THE  FORMATION  AND  GROWTH  OF  BONES.* 

It  is  not  easy  to  explain  in  their  natural  order,  the  various 
parts  of  which  the  human  body  is  composed ; for  they  have 
that  mutual  dependence  upon  each  other,  that  continual  cir- 
cle of  action  and  re-action  in  their  various  functions,  and  that 
intricacy  of  connection,  and  close  dependence,  in  respect  of 
the  individual  parts,  that  as  in  a circle  there  is  no  point  of 
preference  from  which  we  should  begin  to  trace  its  course, 
there  is  in  the  human  body  no  function  so  insulated  from  the 
other  functions,  no  part  so  independent  of  other  parts,  as  to 
determine  our  choice.  We  cannot  begin  without  hesitation, 
nor  hope  to  proceed  in  any  perfect  course ; yet,  from  what- 
ever point  we  begin,  we  may  so  return  to  that  point,  as  to 
represent  truly  this  consent  of  functions,  and  connection  of 
parts,  by  which  it  is  composed  into  one  perfect  whole. 

The  bones  are  framed  as  a basis  for  the  whole  system,  fitted 
to  support,  defend,  and  contain  the  more  delicate  and  noble 
organs.  They  are  the  most  permanent,  unchangeable  parts 
of  all  the  body.  We  see  them  exposed  to  the  seasons,  with- 
out suffering  the  smallest  change ; remaining  for  ages  the 

* I have  arranged  the  preparations  illustrative  of  the  growth  and  structure  of  bone,  so 
as  to  correspond  with  this  dissertation.  They  form  the  first  series  in  tlie  GalJery.  C.  B. 

voii.  I.  A 


OF  THK  FORMATION 


memorials  of  the  dead  ; the  evidence  of  a former  race  of  meia 
exceeding  ours  in  strength  and  stature  ; the  only  remains  of 
creatures  w-hich  no  longer  exist ; the  proofs  of  such  changes 
on  our  globe,  as  vve  cannot  trace  but  by  these  uncertain  marks. 
Thus  we  are  apt  to  conceive,  that  even  in  the  living  body, 
bones  are  hardly  organized,  scarcely  partaking  of  life,  not 
liable,  like  the  soft  parts,  to  disease  and  death.  But  minute 
anatomy,  the  most  pleasing  part  of  our  science,  unfolds  and 
explains  to  us  the  internal  structure  of  the  bones ; shows  their 
myriads  of  vessels,  and  proves  them  to  be  as  full  of  blood  as 
the  most  succulent  and  fleshy  parts ; having,  like  them,  their 
periods  of  growth  and  decay ; as  liable  to  accidents,  and  as 
.subject  to  internal  disease. 

The  phenomena  of  fractured  bones  first  suggested  some  in- 
distinct notions  of  the  way  in  which  bone  might  be  formed. 
It  was  observed,  that  in  very  aged  men,  a hard  crust  was  often 
formed  upon  the  surface  of  the  bones ; that  the  fluid  exuding 
into  the  Joints  of  gouty  people,  sometimes  coagulated  into 
a chalky  mass.  Le  Dran  had  seen  in  a case  of  spina  ventosa, 
or  scrophulous  bone,  an  exudation  which  flowed  out  like  wax, 
and  hardened  into  perfect  bone.  Daventer  had  seen  the 
juice  exuding  from  a split  in  a bone,  coagulate  into  a bony 
crust ; and  they  thought  it  particularly  well  ascertained,  that 
callus  was  but  a coagulable  juice,  which  might  be  seen  exuding 
directly  from  the  broken  ends,  and  which  gradually  coagulated 
into  hard  bone.  The  best  physiologists  did  not  scruple  to  be- 
lieve, that  bones,  and  the  callus  of  broken  bones,  were  formed 
of  a bony  juice,  which  was  deposited  by  the  vessels  of  the 
part,  and  which,  passing  tlu’ough  all  the  successive  conditions 
of  a thin  uncoagulated  juice,  of  a transparent  cartilage,  and 
of  soft  and  flexible  bone,  became  at  last,  by  a slow  coagula- 
tion, a firm,  hard,  and  perfect  bone,  depending  but  little  upon 
vessels  or  membranes,  either  for  its  generation  or  growth,  or 
for  nourishment  in  its  perfect  state.  But  this  coagulation  is  a 
property  of  dead  matter,  which  has  noplace  in  the  living  sys- 
tem ; or  if  blood  or  mucus  do  coagulate  within  the  body,  it 
is  only  after  they  are  separated  from  the  system.  Coagula- 
tion is  a sort  of  accident  in  the  living  body,  and  it  is  not  to  be 
believed  that  the  accidental  concourse  of  parts  should  form 
the  perfect  system  of  a living  bone  ; nor  that  coagulation,  an 
irregular,  uncertain  process,  should  keep  pace  with  the  growth 
of  the  living  parts ; that  a bone  which  is  completely  organized, 
and  a regular  part  of  the  living  system,  should  in  all  its  pro- 
gress towards  this  perfect  state,  be  mere  inanimate,  inorganized 
matter : yet  this  opinion  once  prevailed  ; and  if  other  theories 
were  at  that  time  proposed,  they  did  not  vary  in  any  very  es- 


AND  GROWTH  OF  BONES. 


eential  point  from  this  first  notion.  De  Heide,  a surgeon  of 
Amsterdam,  believed  that  bone  or  callus  was  not  formed 
from  acoagulable  juice,  but  from  the  blood  itself.  He  broke 
the  bones  of  animals,  and,  examining  them  at  various  points  of 
time,  he  never  failed  (like  other  speculators)  to  find  exactly 
what  he  desired  to  find.  In  “ every  experiment,”  he  found  a 
great  effusion  of  blood  among  the  muscles,  and  round  the  bro- 
ken bone ; and  he  as  easily  traced  this  blood  through  all  the 
stages  of  its  progress.  In  the  first  day  red  and  fluid  ; by  and 
by  coagulated ; then  gradually  becoming  white,  then  carti- 
laginous, and  at  last  (by  the  exhalation  of  its  thinner  parts) 
hardening  into  perfect  bone. 

It  is  very  singular,  that  those  who  abjure  theory,  and  appeal 
to  experiments,  who  profess  only  to  deliver  facts,  are  least  of 
all  to  be  trusted  ; for  it  is  theory  which  brings  them  to  try  ex- 
periments, and  then  the  form  and  order,  and  even  the  result 
of  such  experiments,  must  bend  to  meet  the  theories  which 
they  were  designed  to  prove  : it  is  by  this  deception  that  the 
authors  of  two  rival  doctrines  arrive  at  opposite  conclusions, 
by  facts  directly  opposed  to  each  other.  Du  Hamel  believed, 
that  as  the  bark  formed  the  wood  of  a tree,  adding,  by  a sort 
of  secretion,  successive  layers  to  its  growth,  the  periosteum* 
formed  the  bone  at  the  first,  renewed  it  when  spoiled,  or  cut 
away,  and,  when  broken,  assumed  the  nature  of  bone,  and  repair- 
ed the  breach.  He  broke  the  bones  of  pigeons,  and,  allowing 
them  to  heal,  he  found  the  periosteum  to  be  the  chief  organ 
for  re-producing  bone.  He  found  that  the  callus  had  no  ad- 
hesion to  the  broken  bone,  was  easily  separated  from  the  bro- 
ken ends  wdiich  remained  rough  and  bare  ; and,  in  pursuing 
these  dissections,  he  found  the  periosteum  fairly  glued  to  the 
external  surface  of  the  new  bone ; or  he  found  rather  the  cal- 
lus or  regenerated  bone  to  be  but  a mere  thickening  of  the 
periosteum,  its  layers  being  separated,  and  its  substance  swel- 
led. On  the  first  days  he  found  the  periosteum  thickened,  in- 
flamed, and  easily  divided  into  many  lamella,  or  plates ; but 
while  the  periosteum  was  suffering  these  changes,  the  bone 
was  in  no  degree  changed.  On  the  following  days,  he  found 
the  tumour  of  the  periosteum  increased  at  the  place  of  the 
fracture,  and  extending  further  along  the  bone ; its  internal 
surface  already  cartilaginous,  and  always  tinged  with  a little 
blood,  which  came  to  it  through  the  vessels  of  the  marrow. 
He  found  the  tumour  of  the  periosteum  spongy,  and  divisible 
into  regular  layers,  while  still  the  ends  of  the  bone  were  un- 
changed, or  only  a little  roughened  by  the  first  layer  of  the 

* The  periosteum  is  the  membrane  wliich  surrounds  and  is  attached  to  the  sorfacg  of  the 
Iwne,  and  which  conveys  the  blood  vessels  to  it. 


4 


OP  THE  FORMATION 


periosteum  being  already  converted  into  earth,  and  deposited 
upon  the  surlace  of  the  bone  : and  in  the  next  stage  of  its 
progress,  he  found  the  periosteum  firmly  attached  to  the  sur- 
face of  the  callous  mass.  By  wounding,  not  breaking  the 
bones,  he  had  a more  flattering  appearance  still  of  a proof; 
for,  having  pierced  them  with  holes,  he  found  the  holes  fil  ed 
up  with  a sort  of  tompion,  proceeding  from  the  periosteum, 
which  was  thickened  all  round  them.  In  an  early  stage,  this 
plug  could,  by  drawing  the  periosteum,  be  pulled  out  from  its 
hole  : in  a more  advanced  stage,  it  was  inseparably  united  ta 
tbe  bone  so  as  to  supply  the  loss. 

Haller,  doubting  whether  the  periosteum,  a thin  and  deli- 
cate membrane,  could  form  so  large  a mass  of  bone  or  callus, 
repeated  the  proofs,  and  he  again  found  quite  the  reverse  of 
all  this : That  the  callus,  or  the  original  bone,  w’ere  in  no  de- 
gree dependent  on  the  periosteum,  but  were  generated  from 
the  internal  vessels  of  the  bone  itself : That  the  periosteum 
did  indeed  appear  as  early  as  the  cartilage  which  is  to  pro- 
duce the  bone,  seeming  to  bound  the  cartilage,  and  give  it 
form  ; but  that  the  periosteum  was  at  first  but  a loose  tissue  of 
cellular  substance,  without  the  appearance  of  vessels,  or  any 
mark  of  blood,  adhe  ing  chiefly  to  the  heads  or  processes, 
while  it  hardly  touched  the  body  of  the  bone.  He  also  found 
that  the  bone  grew,  became  vascular,  bad  a free  circulation  of 
red  blood,  and  that  then  only  the  vessels  of  the  periosteum 
began  to  carry  red  blood,  or  to  adhere  to  the  bone.  We 
know  that  the  bones  begin  to  form  in  small  nuclaei,  in  the  very 
centre  of  their  cartilage,  or  in  the  very  centre  of  the  yet  flex- 
ible callus,  far  from  the  surface,  where  they  might  be  assisted 
by  the  periosteum. 

Thus  has  the  formation  of  bone  been  falsely  attributed  to  a 
gelatinous  effusion,  giadually  hardened;  or  to  that  blood  which 
must  be  poured  out  from  the  ruptured  vessels  round  the  frac- 
tured bone  ; or  to  the  induration  and  change  of  the  periosteum, 
depositing  layer  after  layer,  till  it  completed  the  form  of  the 
bone. 

But  when,  neglecting  theory,  we  set  ourselves  to  examine^ 
with  an  unbiassed  judgment,  the  process  of  nature  in  form- 
ing the  bones,  as  in  the  chick,  or  in  restoring  them,  as  in 
broken  limbs,  a succession  of  phenomena  present  themselves^ 
the  most  orderly,  beautiful,  and  simple  of  any  that  are  record- 
in  the  philosophy  of  the  animal"  body  : for  if  bones  were  but 
condensed  gluten,  coagulated  blood,  or  a mere  deposition  from 
the  periosteum,  they  were  then  inorganized,  and  out  of  the 
system,  not  subject  to  change,  nor  open  to  disease  ; liable,  in- 
deed, to  be  broken,  but  without  any  means  of  being  healed 


AND  GROWTH  OF  BONES. 


5 


again  ; while  they  are,  in  truth,  as  fully  organized,  as  permeable 
to  the  blood,  as  easily  hurt,  and  as  easily  healed,  as  sensible  t® 
pain,*  and  as  regularly  changed  as  the  softer  parts  are.  We 
are  not  to  refer  the  generation  and  growth  of  bone  to  any 
other  part.  It  is  not  formed  by  that  jelly  in  which  the  bone 
is  layed,  nor  by  the  blood  which  is  circulating  in  it,  nor  by  the 
periosteum  which  covers  it,  nor  by  the  medullary  membrane 
with  which  it  is  lined  ; but  the  whole  system  of  the  bone,  of 
which  these  are  parts  only,  is  designed  and  planned,  is  laid  out 
in  the  very  elements  of  the  body,  and  goes  on  to  ripeness,  by 
the  concurring  action  of  all  its  parts.  The  arteries,  by  a de- 
termined action,  deposite  the  bone  ; which  is  formed  common- 
ly in  a bed  of  caitilage,  as  the  bones  of  the  leg  or  arm  are; 
sometimes  betwixt  two  layers  of  membrane,  like  the  bones  of 
the  skull,  where  true  cartilage  is  never  seen.  Often  the  se- 
cretion of  the  bony  matter  is  performed  in  a distinct  bag,  and 
there  it  grows  into  form,  as  in  the  teeth  ; for  each  tooth  is 
formed  in  its  little  bag,  which,  by  injection,  can  be  filled  and 
covered  with  vessels.f  Any  artery  of  the  body  may  assume 
this  action  and  deposite  bone,  w’hich  is  formed  also  where  it 
should  not  be,  in  the  tendons,  and  in  the  joints,  in  the  great  ar- 
teries, and  in  their  valves,  in  the  flesh  of  the  I eart  itself,  or 
even  in  the  soft  and  pulpy  substance  of  the  brain. | 

In  the  human  foetus,  and  in  other  animals,  before  the  time 
of  birth,  instead  of  bones,  there  are  only  cartilages  of  the 
form  of  the  future  bone.  The  whole  foetus  appears  to  the  eye 
like  a mere  jelly  : the  bones  are  a pure,  almost  transparent, 
and  tremulous  jelly  ; they  are  flexible,  so  that  a long  bone 
can  be  bended  into  a complete  ring ; and  no  opacity  nor  spot 
of  ossification  is  seen. 

This  cartilage  never  is  hardened  into  bone  ; but,  from  the 
first,  it  is  in  itself  an  organized  mass.  It  has  its  vessels, 
which  are  at  first  transparent,  but  which  soon  dilate;  and  when- 
ever the  red  colour  of  the  blood  begins  to  appear  in  them, 
ossification  very  quickly  follow's,  the  arteries  being  so  far  en- 
larged as  to  carry  the  coarser  parts  of  the  blood.  The  first 
mark  of  ossification  is  an  artery,  which  is  seen  running  into  the 
centre  of  the  jelly,  in  which  the  bone  is  to  be  formed.  Other 
arteries  soon  appear,  overtake  the  first,  mix  with  it,  and  form 
a net  work  of  vessels ; then  a centre  of  ossification  begins, 
stretching  its  rays  according  to  the  length  of  the  bone,  and 

* The  ob'curitv  on  this  subject  is  from  the  neglect  of  defined  terms.  W>  siiall  present- 
ly see  that  t!ie  sensibility  posse«sed  by  the  bones,  and  tlie  kind  of  pain  to  wliich  they  are 
subject,  differs  from  the  sensibility  and  pain  of  the  .skin  and  soft  parts.  C.  B. 

f The  bone  of  the  tooth  is  formed  in  a manner  very  different  from  common  hone.  C.  B. 

t The  structure  of  the  tnie  and  natural  bone  is  difiereHt  from  the  preternatural  bony 
fOncretioDs  ia  the  vessels  and  membranes.  C,  B. 


OF  THE  FORMATION 


6‘ 

then  the  cartilage  begins  to  grow  opaque,  yellow,  brittle  ; if, 
will  no  longer  bend,  and  the  small  nucleus  of  ossification  is 
felt  in  the  centre  of  the  bone,  and  when  touched  with  a sharp 
point,  is  easily  known  by  its  gritty  feel.  Other  points  of  ossi- 
fication are  successively  formed  ; always  the  ossification  is  fore- 
tohl  by  the  spreading  of  the  artery,  and  by  the  arrival  of  red 
blood.  Every  point  of  ossification  has  its  little  arteries,  and 
each  ossifying  nucleus  has  so  little  dependence  on  the  carti- 
lage in  which  it  is  formed,  that  it  is  held  to  it  by  vessels  only ; 
and  when  the  ossifying  cartilage  is  cut  into  thin  slices,  and 
steeped  in  water  till  its  arteries  rot,  the  nucleus  of  ossification 
drops  spontaneously  from  the  cartilage,  leaving  the  cartilage 
like  a ring,  with  a smooth  and  regular  hole  where  the  bone 
lay. 

The  colour  of  each  part  of  a bone  is  proportioned  exactly 
to  the  degree  in  which  its  ossification  is  advanced.  When  os- 
sification begins  in  the  centre  of  the  bone,  redness  also  ap- 
pears, indicating  the  presence  of  those  vessels  by  which  the 
bony  matter  is  to  be  poured  out.  When  the  bony  matter  be- 
gins to  accumulate,  the  red  colour  of  those  arteries  is  obscur- 
ed, the  centre  of  the  bone  becomes  yellow  or  white,  and  the 
colour  removes  towards  the  ends  of  the  bone.  In  the  centre, 
the  first  colouring  of  the  bone  is  a cloudy,  diffused,  and  general 
red,  because  the  vessels  are  profuse.  Beyond  that,  at  the 
edges  of  the  first  circle,  the  vessels  are  more  scattered  and 
asunder,  distinct  trunks  are  easily  seen,  forming  a circle  of 
I’adiated  arteries,  which  point  towards  the  heads  of  the  bone. 
Beyond  that,  again,  the  cartilage  is  transparent  and  pure,  as 
yet  untouched  with  blood  ; the  arteries  have  not  reached  it, 
and  its  ossification  is  not  begun.  Thus,  a long  bone,  while 
forming,  seems  to  be  divided  into  seven  various  coloured 
zones.  The  central  point  of  most  perfect  ossification  is  yel- 
low and  opaque.  On  either  side  of  that,  there  is  a zone  of 
red.  On  either  side  of  that,  again,  the  vessels  being  more 
sparse,  form  a vascular  zone,  and  the  zone  at  either  end  is 
transparent  or  white.*  The  ossification  follows  the  vessels, 

* It  is  curious  to  observe  how  completely  vaseular  the  bone  of  a chicken  is  before  the 
ossification  liave  fairly  begun  ; liow  the  ossification  being  begun,  overtakes  the  arteries,  and 
hides  them,  changing  tlie  transparent  and  vascular  part  of  the  bone  into  an  opaque 
white ; how,  by  pealing  off  the  periosteum,  bloody  dots  are  seen,  which  show  a living  con- 
nection and  commerce  of  vessels  betwixt  the  periosteum  and  tile  bone ; how  b^  tearing  up 
the  outer  layers  of  the  tender  bone,  the  vascularity  of  the  inner  layers  is  again  expos^  ; 
and  the  most  beautiful  proof  of  all  is  that  of  our  common  preparations,  where,  by  filling 
with  injection  the  arteries  of  an  adult  hone,  by  its  nutritious  vessels,  and  then  corroding 
the  hone  with  mineral  acids,  we  dissolve  the  eaitji,  leaving  notliing  but  the  transparent  jel- 
ly, which  restores  it  to  its  original  cartilaginous  state;  and  then  tlie  vessels  appear  in  suclr 
profusion,  that  the  bone  may  be  compared  in  vascularity  with  the  soft  parts,  and  it  is  seen 
that  its  arteries  were  not  annihilated,  but  its  high  vascularity  only  concealed  by  the  depo« 
sition  of  the  bony  part. 


AND  GROWTH  OR  BONES. 


-and  buries  and  hides  those  vessels  by  which  it  is  formed  : 
The  yellow  and  opaque  part  expands  and  spreads  along  the 
bone  : The  vessels  advance  towards  the  heads  of  the  bones : 
The  whole  body  of  the  bone  becomes  opaque,  and  there  is 
left  only  a small  vascular  circle  at  either  end  ; the  heads  are 
separated  from  the  body  of  the  bone  by  a thin  cartilage,  and 
the  vessels  of  the  centre,  extending  still  towards  the  extremi- 
ties of  the  bone,  perforate  that  cartilage,  pass  into  the  head  of 
the  bone,  and  then  its  ossification  also  begins,  and  a small 
nucleus  of  ossification  is  formed  in  its  centre.  Thus  the  heads 
and  the  body  are,  at  the  first,  distinct  bones,  formed  apart,  join- 
ed by  a cartilage,  and  not  united  till  the  age  of  fifteen  or 
twenty  years. 

The  vessels  are  seen  entering  in  one  large  trunk  (the  nutri- 
tious artery)  into  the  middle  of  the  bone:  From  that  centre 
they  extend  in  a radiated  form  towards  either  end,  and  the 
fibres  of  the  bone  are  radiated  in  the  same  direction  ; there 
are  furrows  betwixt  the  rays,  and  the  arteries  run  along  in  the 
furrows  of  the  bone,  as  if  the  arteries'  were  forming  these 
ridges,  secreting  and  pouring  out  the  bony  matter,  each  artery 
piling  it  up  on  either  side  to  form  its  ridge. f The  body  of  the 
bone  is  supplied  by  its  own  vessels ; the  heads  of  the  bone  are 
in  part  supplied  by  the  extremities  of  the  same  trunks  which 
perforate  the  dividing  cartilage  like  a sieve  ; the  periosteum 
adhering  more  firmly  to  the  heads  of  the  bone  brings  assist- 
ant arteries  from  without,  which  meet  the  internal  trunks,  and 
assist  the  ossification ; which,  with  every  help,  is  not  accom- 
plished in  many  years. 

It  is  by  the  action  of  the  vessels  that  all  the  parts  of  the  hur 
man  body  are  formed,  fluids  and  solids,  each  for  its  respective 
use  : the  blood  is  formed  by  the  action  of  the  vessels,  and  all 
the  fluids  are  in  their  turn  formed  from  the  blood.  We  see  in 
the  chick,  where  there  is  no  external  source  from  which  its 
red  blood  can  be  derived,  that  red  blood  is  formed  within  its 
own  system.  Every  animal  system,  as  it  grows,  assimilates  its 
food,  and  converts  it  to  the  animal  nature,  and  so  increases 
the  quantity  of  its  red  blood : and  as  the  red  blood  is  thus  pre- 
pared by  the  actions  of  the  greater  system,  the  actions  of  par- 
ticular vessels  prepare  various  parts : some  to  be  added  to  the 
mass  of  solids,  for  the  natural  growth  ; others  to  supply  the 
continual  waste ; others  to  be  discharged  from  the  body  as 
effete  and  hurtful,  or  to  allow  new  matter  to  be  received  j 

* The  arteries  of  a hone  branch  rrith  freedom,  and  with  the  same  seeming  irregularity  as 
in  other  parts  of  the  body.  The  arteries  do  not  exude  their  secretion  from  their  aides,  so 
aa  to  pile  up  the  ridge  of  bone  in  their  course.  Tlis  secretion  seems  to  be  performed  ii 
their  very  extremities,  C.  B. 


8 


OF  THE  FORMATION 


Others  again  to  perform  certain  offices  within  the  body,  as 
semen,  saliva,  bile,  or  urine.  Thus  the  body  is  furnished  with 
various  apparatus  for  performing  various  offices,  and  for  re- 
pairing the  waste.  These  are  the  secretions,  and  the  forma- 
tion of  bone  is  one  of  these.  The  plan  of  the  whole  body 
lies  in  the  embryo,  in  perfect  order,  with  all  its  forms  and  parts. 
Cartilage  is  laid  in  the  place  of  bone,  and  preserves  its  form 
for  the  future  bone,  with  all  its  apparatus  of  surrounding  mem- 
branes, its  heads,  its  processes,  and  its  connection  with  the  soft 
parts  The  colourless  arteries  of  this  pellucid  but  organized 
mass  of  cartilage  keep  it  in  growth,  extend,  and  yet  preserve 
its  form,  and  gradually  enlarging  in  their  own  diameter,  at  last 
receive  the  entire  blood.*  Then  the  deposition  of  earthy 
matter  begins-  The  bone  is  deposited  in  specks,  which  spread 
and  meet  and  form  themselves  into  perfect  bone.  While  the 
bone  is  laid  by  arteries,  the  cartilage  is  conveyed  away  by  the 
absorbing  ves.sels ; and  while  they  convey  away  the  super- 
fluous cartilage,  they  model  the  bone  into  its  due  form,  shape 
out  its  cavities,  cancelli,  and  holes,  remove  the  thinner  parts 
of  the  cartilage,  and  harden  it  into  due  consistence. 

If  such  organization  of  arteries  to  deposite  bone,  and  ab- 
sorbents to  take  up  the  cartilage,  and  make  room  for  the 
osseous  matter,  be  necessaiy  in  the  formation  and  growth,  it 
is  no  less  necessary  for  the  life  and  health  of  the  full  formed 
bone.  Its  health  depends  on  the  regular  deposition  and  re- 
absorption. moulding  and  forming  the  parts;  and  by  various 
degrees  of  action,  bone  is  liable  to  inflame,  ulcerate,  to  rot 
and  spoil,  to  become  brittle  by  too  much  secreted  earth,  or 
to  become  soft  by  a greedy  diseased  absorption  of  its  earthy 
parts.  The  earth,  which  constitutes  the  hardness,  and  all  the 
useful  properties  of  bone,  is  dead,  inorganized,  and  lies  in  the 
interstices  of  the  bone,  w'here  it  is  made  up  with  mucus,  to 
give  it  consistence  and  strength  ; furnished  with  absorbents  to 
keep  it  in  health,  and  carry  off  its  wasted  parts;  and  pervaded 
by  vessels  to  supply  it  wdth  new  patter.  The  cartilage  is  in 
itself  a secretion,  to  which  the  full  secretion  ol  bone  succeeds, 
as  the  arteries  grow  stronger  in  their  secreting  office  : for  in  a 
broken  limb  there  is  first  a thin  effusion,  then  a tremulous 
jelly,  then  radiated  vessels,  then  ossifying  spots,  and  these 

* Previous  to  the  forraaflon  of  bone  (or  the  preparation  for  it)  in  the  cartilaffe,  there  is 
no  proof  of  there  jjeing  vessels  in  it.  But  we  presume  that  the  cartilage  must  have  vessels, 
becauseit  grows  willi  the  growth  of  the  animal,  previous  to  the  formation  of  bone  in  it. 

However,  the  change,  previou-^  to  the  deposition  of  bone,  has  not  been  noticed-  the  firm 
cartilage  sufflTs  a change ; theri?  is  a tract  from  the  circumi’erence  to  the  centre  of  it,  in 
which  the  firm  cartilage  is  dis-so’^-ed  j and  in  the  spot  where  the  first  particle  of  bone  h to 
be  deposited,  there  is  a lilde  soft  well  of  matter,  different  from  the  firm  substance  «f  the 
cartilage.  C.  B. 


AND  GROWTH  OF  BONES. 


running  together,  form  a perfect  bone.*  If  the  broken  limb 
be  too  much  moved  during  the  cure,  then  are  the  secreting  ar- 
teries interupted  in  their  office,  perfect  bone  is  never  formed,  it 
remains  a cartilage,  and  an  unnatural  joint  is  produced ; the 
vessels  are  opened  again,  the  process  is  renewed,  and  the 
bones  unite ; or  even  by  rubbing,  by  stimulating,  by  merely 
cutting  the  surrounding  parts,  the  vessels  are  made  active, 
and  their  secretion  is  renewed.  During  all  the  process  of 
ossification,  the  absorbents  proportion  their  action  to  the  sti- 
mulus which  is  applied  to  them ; they  carry  away  the  serous 
fluid,  when  jelly  is  to  take  its  place ; they  remove  the  jelly, 
as  the  bone  is  laid  ; they  continue  removing  the  bony  particles 
also,  which  (as  in  a circle)  the  arteries  continually  renew. 

Nothing  can  be  more  curious  than  this  continual  renovation 
and  change  of  parts,  even  in  the  hardest  bones.  We  are 
accustomed  to  say  of  the  whole  body,  that  it  is  daily  changed ; 
that  the  older  particles  are  removed,  and  new  ones  supply 
their  place  ; that  the  body  is  not  now  the  same  individual 
body  that  it  was ; but  it  could  not  be  easily  believed  that  we 
speak  only  by  guess  concerning  the  softer  parts,  what  we 
know  for  certain  of  the  bones.  It  was  discovered  by  chance 
that  animals  fed  upon  the  refuse  of  the  dyer’s  vats,  received 
so  much  of  the  colouring  matter  into  the  system,  that  the 
bones  were  tinged  by  the  madder  to  a deep  red,  while  the 
softer  parts  were  unchanged ; no  tint  remaining  in  the  liga- 
ments nor  cartilages,  membranes,  vessels,  nor  nerves,  not 
even  in  the  delicate  vessels  of  the  eye.  It  was  easy  to  distin- 
guish by  the  microscope,  that  such  colour  was  mixed  with 
the  bony  matter,  resided  in  the  interstices  only,  but  did  not 
remain  in  the  vessels  of  the  bone,  which,  like  those  of  all 
the  body,  had  no  tinge  of  red  ; while  our  injections  again  fill 
the  vessels  of  the  bone,  make  all  their  branches  red,  but  do 
not  affect  the  colours  of  the  bony  part.  When  madder  is 
given  to  animals,  withheld  for  some  time,  and  then  given 
again,  the  colour  appears  in  their  bones,  is  removed,  and 
appears  again  wth  such  a sudden  change  as  proves  a rapidity 
of  deposition  and  absorption,  exceeding  all  likelihood  or 
belief.  All  the  bones  are  tinged  in  twenty-four  hours;  in 
two  or  three  days  their  colour  is  very  deep ; and  if  the  mad- 

* The  matter  may  be  thus  stated : the  extravasated  blood  being  absorbed,  an  eflheion  is 
poured  out  by  the  vessels  of  the  broken  bone.  This  matter  is  a regular  secretion,  it  ap-- 
pears  to  the  eye  like  a uniform  jeUy ; but  so  does  the  embryo  itself.  It  is  bone  in  embryo, 
the  membranes  and  vessels,  arteries,  veins,  and  absorbents  are  in  if ; the  arteries  of  the  sur- 
rtMnding  parts  do  not  shoot  into  it,  but  veins,  as  well  as  arteries  and  absorbents,  inosculate 
with  the  vessels  of  this  new  formed  matter ; and  whatever  vessels  may,  by  accidental  con- 
tMt,  inosculate  with  this  substance,  whether  coming  from  bone,  muides,  or  membrane, 
still  bone  is  form^,  because  it  is  the  destined  constitution  of  the  new  fonoed  naa.ss.  or  rather 
«f  the  vessels  which  are  already  in  it  to  form  bone.  C.  B. 

B 


10 


OF  THE  FORMATION. 


der  be  left  off  but  for  a few  days,  the  red  colour  is  entirely 
removed. 

This  tinging  of  the  bones  with  madder,  was  the  great  in- 
strument in  the  hands  of  Du  Hamel,  for  proving  by  demon- 
stration, that  it  was  by  layers  from  the  periosteum  that  the 
bone  was  formed ; and  how  very  far  the  mind  is  vitiated  by 
this  vanity  of  establishing  a doctrine  on  facts,  is  too  easily 
seen  here.  Du  Hamel,  believing  that  the  periosteum  deposi- 
ted successive  layers,  which  were  added  to  the  bone,  it  was 
his  business  to  prove  that  the  successive  layers  would  be  de- 
posited alternately  red,  white,  and  red  again,  by  giving  a 
young  animal  madder,  withholding  it  for  a little  while,  and 
then  beginning  again  to  give  it.  Now,  it  is  easy  to  forsee  that 
this  tinging  of  the  lamellse  should  correspond  with  the  succes- 
sive times  in  which  the  periosteum  is  able  to  deposite  the  lay- 
ers of  its  substance,  but  Du  Hamel  very  thoughtlessly  makes 
his  layers  correspond  only  with  the  weeks  or  months  in  which 
his  madder  was  given  or  withheld.  It  is  easy  to  foresee  also, 
that  if  madder  be  removed  from  the  bones  in  a few  days, 
(which  he  hiinself  has  often  told  us,)  then  his  first  layer,  viz.  of 
red  bone,  could  not  have  waited  for  his  layer  of  white  to  be 
laid  above  it,  nor  for  a layer  of  red  above  that  again,  so 
that  he  should  have  been  able  to  show  successive  layers  : And 
if  madder  can  so  penetrate  as  to  tinge  all  the  bones  that  are 
already  formed,  then,  though  there  might  be  first  a tinged 
bone,  then  a white  and  colourless  layer,  whenever  he  proceed- 
ed to  give  madder  for  tinging  a third  layer,  it  would  pervade 
all  the  bone,  tinge' the  layer  below,  and  reduce  the  whole  into 
one  tint.  If  a bone  should  increase  by  layers,  thick  enough 
to  be  visible,  and  of  a distinct  tint,  and  such  layers  be  conti- 
nually accumulated  upon  each  other  every  week,  what  kind 
of  a bone  should  this  gi'ow  to  ? Yet  such  is  the  fascinating  na- 
ture of  a theory,  that  Du  Hamel,  unmindful  of  any  interrup- 
tions like -those,  describes  boldly  his  successive  layers,  carry- 
ing us  through  regular  details,  experiment  after  experiment, 
till  at  last  he  brings  up  his  report  to  the  amount  of  five  succes- 
sive layers,  viz.  two  red  layers,  and  three  white  ones.  And 
in  one  experiment  he  makes  the  tinge  of  the  madder  continue 
in  the  bones  for  six  months,  forming  successive  layers  of  red 
and  white,  although  in  an  earlier  experiment  (which  he  must 
have  forgotten  in  hishurr)-)  he  tells  us,  that  by  looking  through 
the  transparent  part  of  a cock’s  wing,  he  had  seen  the  tinge  of 
the  madder  gradually  leave  the  bones  in  not  many  days. 

These  experiments  are  as  gross  and  palpable  as  the  occa- 
sion of  them,  and  should  stand  as  a warning  to  us,  showing 
how  severely  and  honestly  we  must  question  our  own  judg- 


AND  GROWTH  OF  BONES. 


11 


rnent,  when  trying  to  confirm  our  preconceived  theories  by 
experiments  and  facts.* 

Yet,  by  these  experiments  with  madder,  one  most  impor- 
tant fact  is  proved  to  us ; that  the  arteries  and  absorbents, 
acting  in  concert,  alternately  deposite  and  re-absorbthe  earthy 
pai  tides,  as  fast  as  can  be  conceived,  of  the  soft  parts,  or  even 
of  the  most  moveable  and  fluctuating  humours  of  the  body. 
The  absorption  of  the  hardest  bones  is  proved  by  daily  obser- 
vation ; when  a carious  bone  disappears  before  the  integu- 
ments are  opened  ; when  a tumour,  pressing  upon  a bone, 
destroys  it ; when  an  aneurism  of  the  temporal  artery  destroys 
the  skull ; when  an  aneurism  of  the  heart  beats  open  the  tho- 
rax, destroying  the  sternum  and  ribs ; when  an  aneurism  of 
the  ham  destroys  the  tbigh-bone,  tibia,  and  joint  of  the  knee ; 
when  a tumour  coming  from  within  the  head,  forces  its  way 
through  the  bones  of  the  skull ; — in  all  these  cases,  since  the 
bone  cannot  be  annihilated,  what  can  happen,  but  that  it  must 
be  absorbed  and  conveyed  away  ^ If  we  should  need  any 
stronger  proofs  than  these,  we  have  molities  ossium,  a dis- 
ease by  which,  in  a few  months,  the  bony  system  is  entirely 
broken  up,  and  conveyed  away,  by  a high  action  of  the  ab- 
sorbents, with  continual  and  deep-seated  pain ; a discharge  of 
the  earthy  matter  by  the  urine ; a gradual  softening  of  the 
bones,  so  that  they  bend  under  the  weight  of  the  body ; jhe 
heels  are  turned  up  behind  the  head  ; the  spine  is  crooked ; 
the  pelvis  distorted  ; the  breast  crushed  and  bent  in : and  the 
functions  beginning  to  fall  low,  the  patient,  after  a slow  hectic 
fever,  long  and  much  suffering  of  pain  and  misery,  expires, 
with  all  the  bones  distorted  in  a shot  king  degree,  gelatinous, 
or  nearly  so,  robbed  of  all  their  earthy  parts,  and  so  thoroughly 
softened  as  to  be  cut  with  the  knife.f 

Thus,  every  bone  has,  like  the  soft  parts,  its  arteries,  veins, 
and  absorbent  vessels ; and  every  bone  has  its  nerves  too. 
We  see  them  entering  into  its  substance  in  small  threads,  as 
on  the  surfaces  of  the  frontal  and  parietal  bones:  We  see 
them  entering  for  particular  purposes,  by  a large  and  peculiar 
hole,  as  the  nerves  which  go  into  the  jaws  to  reach  the  teeth  : 
We  find  delicate  nerves  going  into  each  bone  along  with  its 
nutritious  vessels;  and  yet  we  dare  hardly  believe  the  demon- 
stration, since  bones  seem  quite  insensible  and  dead  : We 
have  ho  pain  when  the  periosteum  is  rasped  and  scraped  from 

* However  just  this  criticism  is  upon  the  reasoning  of  Du  Hamel,  yet  I believe  in  tire 
facts  stated.  In  my  Collection  may  be  seen  the  bone  of  a pig  showing  three  distinct  layers, 
distinguishable  in  colour.  C.  B. 

+ See  the  examples  of  distortion  in  the  Museum,  Windmill  Street,  and  in  particular  the 
skeleton  of  a woman  who  died  in  consequence  of  the  Caesarean  operation.  C.  B 


12 


OP  THE  FORMATION 


a bone  : We  have  no  feeling  when  bones  are  cut  in  amputa- 
tion; or  when,  in  a broken  limb,  we  cutoff  with  pincers,  the 
protruding  end  of  a bone  : We  feel  no  pain  when  a bone  is 
trepanned,  or  when  caustics  are  applied  to  it ; and  it  has  been 
always  known,  that  the  heated  irons  which  the  old  surgeons 
used  so  much,  made  no  other  impression  than  to  excite  a par- 
ticular titillation  and  heat,  rather  pleasant  than  painful,  run- 
ning along  the  course  of  the  bone.  But  there  is  a deception  in 
all  this.  A bone  may  be  exquisitely  sensible,  and  yet  give  no 
pain ; a paradox  which  is  very  easily  explained.  A bone  may  feel 
acutely  and  yet  not  send  its  sensation  to  the  brain.  It  is  not 
fit  that  parts  should  feel  in  this  sense,  which  are  so  con- 
tinually exposed  to  shocks  and  blows,  and  all  the  accidents  of 
life ; which  have  to  suffer  all  the  motions  which  the  other 
parts  require.  In  this  sense,  the  bones,  the  cartilages,  liga- 
mints,  bursse,  and  all  the  parts  that  relate  to  joints,  are  quite 
insensible  and  dead.  A bone  does  not  feel,  or  its  feelings  are 
not  conveyed  to  the  brain : but,  except  in  the  absence  of  pain, 
it  shows  every  mark  of  life.  Scrape  a bone  and  its  vessels 
bleed ; cut  or  bore  a bone,  and  its  granulations  sprout  up ; 
break  a bone,  and  it  will  heal ; or  cut  a piece  of  it  away,  and 
more  bone  will  readily  be  produced  ; hurt  it  any  way,  jind  it 
inflames ; burn  it,  and  it  dies : take  any  proof  of  sensibility, 
but  the  mere  feeling  of  pain,  and  it  will  answer  to  the  proof. 
In  short,  these  parts  have  a sensibility  which  belongs  to  them- 
selves, but  have  no  feelings  in  correspondence  with  the  gene- 
ral system.* 

A bone  feels  stimuli,  and  is  excited  to  re-act ; injuries  pro- 
duce inflammation  in  tbe  bones,  as  in  the  soft  parts ; and  then 
swelling  and  spongy  looseness,  and  a fullness  of  blood,  suppu- 
ration, ulcer,  and  the  death  and  discharge  of  the  diseased  bone 
ensue.  When  the  texture  of  a bone  is  thus  loosened  by  in- 
flammation, its  feeling  is  roused ; and  the  hidden  sensibility 

* Prom  the  consideration  of  these  facts,  together  with  this  most  essential  one,  viz.  that 
bones,  ligaments,  and  tendons  are  actually  capable  of  receiving  and  propagating  painful  im- 
pressions to  the  sensorium,  I liave  come  to  tlie  following  conclusion  : — The  sensation  of  pain 
is  bestowed  as  a safeguard  to  the  frame,  forcing  us  to^avoid  whatever  is  hurtful.  To  this 
effect,  sensibility  varira  in  different  parts,  and  in  general  the  sensibility  of  tlie  more  superfi- 
cial parts,  being  sufficient  protection  to  the  parts  beneath,  the  deep  parts  are  but  little  sensi- 
ble. The  sensibility  possessed  by  the  skin  would  not  he  sufficient  protection  to  the  eye; 
such  parts  differ  in  kind  of  sensibility  as  well  as  in  degree.  Experiments  have  been  made 
by  cutting  and  burning  the  bones  and  tendons,  and  the  conclusion  has  been,  that  they  were 
insensible.  But  when  a man  sprains  his  ankle-joint,  he  is  in  extreme  pain,  though  he  can 
easily  satisfy  himself  that  the  pain  he  feels  is  not  in  the  skin,  but  must  be  in  the  joint  and 
tendons.  It  appears  then,  that  such  parts  usually  thought  insensible,  feel  pain  and  can  pro- 
pagate that  pain  to  the  sensorium ; and  further,  that  the  peculiar  sensibilities  are  so  suited  as 
to  allow  of  the  free  and  natural  motion  and  of  the  necessary  degree  of  attrition,  but  are  bo- 
stowed  for  the  purpose  of  making  us  avoid  that  degree  of  violence,  which  would  endanger 
the  texture  or  healthy  function  of  the  part.  C.  B. 


AND  GKOWTH  OF  BONES.  13 

of  the  bone  rises  up  like  a new  property  of  its  nature  : and  as 
the  eye,  the  skin,  and  all  feeling  parts  have  their  sensibility  in- 
creased by  disease,  the  bones,  ligaments,  bursae,  and  all  the 
parts  whose  feeling  during  health,  is  obscure  and  hardly  known, 
are  roused  to  a degree  of  sensibility  far  surpassing  the  soft 
parts.  The  wound  of  a joint  is  indeed  less  painful  at  first, 
but  when  the  inflammation  comes,  its  sensibility  is  raised  to  a 
dreadful  degree  : the  patient  cries  out  with  anguish.  No 
pains  are  equal  to  those  which  belong  to  the  bones  and  joints. 

This  ossification  is  a process  of  a truly  animal  nature  : no 
coagulation  will  harden  cartilage  into  bone  ; no  change  of  con- 
sistence will  form  the  blood  into  it ; no  condensation  of  the 
periosteum  can  assimilate  it  to  the  nature  of  a bone.  Bone 
is  not  the  inorganic  concrete  which  it  was  once  supposed,  but 
is  a regularly  organized  part,  whose  form  subsists  from  the 
first,  which  is  perfected  by  its  secreting  arteries,  balanced,  as 
in  every  secretion,  by  the  absorbents  of  the  part;  it  lives, 
grows,  and  feels,  is  liable  to  accidents,  and  subject  to  disease. 
Ossification  is  a process  which,  at  first,  appears  so  rapid,  that 
we  should  expect  it  to  be  soon  complete  ; but  it  becomes 
in  the  end,  a slow  and  difficult  process.  It  is  rapid  at  first ; it 
advances  slowly  after  birth ; it  is  not  completed  till  the 
twentieth  year ; it  is  forwarded  by  health  and  strength,  retard- 
ed by  weakness  and  disease.  In  scrophula  it  is  imperfect ; 
and  so  children  become  rickety,  when  the  bones  soften  and 
swell  at  their  heads,  and  bend  under  the  weight  of  the  body. 
And  why  should  we  be  surprised,  that  carelessness  of  food  or 
clothing,  bad  air,  or  languid  health,  should  cause  that  dread- 
ful disease,  when  more  or  less  heat,  during  the  incubation  of  a 
chick,  prevents  the  growth  of  its  bones;  when  the  sickness  of 
a creature,  during  our  experiments,  protracts  the  growth  of 
callus ; when,  in  the  accidents  of  pregnancy,  of  profuse  suppu- 
ration, or  of  languid  health,  the  knitting  of  broken  bones  is 
delayed,  or  prevented  quite  ? 

This  process,  so  difficult  and  slow,  is  assisted  by  every  pro- 
vision of  nature.  The  progress  of  the  whole  is  slow,  that  so 
long  as  the  body  increases  in  stature,  the  bones  also  may  grow ; 
but  it  is  assisted  in  the  individual  parts,  where  some  are  slow, 
some  rapid  in  their  growth,  some  delayed,  as  the  heads  of  joints, 
that  their  bones  may  be  allowed  to  extend,  and  others  hasten- 
ed, as  the  pelvis,  that  it  may  acquire  its  perfect  size  early  in 
life.  Ossification  is  assisted  by  the  softness  of  the  cartilagi- 
nous bed  in  which  the  bone  is  formed ; by  those  large  and  per- 
meable vessels  which  carry  easily  the  grosser  parts  of  the 
blood  ; by  a quick  and  powerful  absorption,  which  all  along 


14 


OF  THE  FORMATION 


is  modelling  the  bone;  and,  most  of  all,  by  being  formed  in 
detached  points,  multiplied  and  crowded  together,  wherever 
much  bone  is  required. 

There  is  one  central  ring  first  ossified  in  a long  bone,  as  of 
the  leg  or  arm ; the  heads  or  ends  of  the  bone  are  at  first 
mere  cartilage,  but  they  also  soon  begin  to  ossify ; the  body 
stretches  in  a radiated  form  towards  either  head ; the  heads 
ossifying  each  in  its  centre,  also  stretch  towards  the  bone  ; the 
heads  meet  the  body,  and  join  to  it ; a thin  cartilage  only 
is  interposed,  which  grows  gradually  thinner  till  the  twentieth 
year,  and  then  disappears,  the  body,  heads,  and  processes,  be- 
coming one  bone.  In  fiat  bones, as  in  the  skull,  ossification 
goes  from  one  or  more  central  points,  and  the  radiated  fibres 
meet  the  radii  of  other  ossifying  points,  or  meet  the  edges  of 
the  next  bone.  See  plate  I.  fig.  3 and  4.  The  thick  round 
bones  which  form  the  wrist  and  foot,  have  one  ossification  in 
their  centre,  which  is  bounded  by  cartilage  all  round.  The 
processes  are  often  distinct  ossifications  joined  to  the  bones, 
like  their  heads,  and  slowly  consolidated  with  them  into  firm 
bones  f 

While  the  bone  is  forming,  various  parts,  essential  to  its  sys- 
tem, gradually  rise  into  view.  At  first  we  cannot  in  the  long 
bone  perceive  any  heads,  processes,  cavities,  or  cells;  these 
parts  are  very  slowly  formed,  and  are  perfected  only  in  the 
adult  bone. 

At  first,  the  whole  length  of  a long  bone  is  represented  by 
a transparent  jelly,  where  there  is  no  distinction  of  heads  nor 
processes ; it  is  all  of  one  mass.  After  the  red  blood  has  be- 
gun to  tinge  this  cartilage,  the  ossification  begins,  and  one  ring 
is  formed  in  the  middle  of  the  bone  : from  this  ring  the  fibres 

* The  csBification  of  the  Hat  bones  is  a subject  too  curious  to  be  omitted  in  this  disserta- 
tion. The  brain  of  the  foetus  wliile  of  the  size  of  a liazle-nut  is  invested  with  a membrane 
in  wliich  there  is  as  yet  no  speck  of  bone.  In  the  third  month,  the  ossification  of  the  cra- 
nial bones  commence,  and  the  fiist  process  exhibits  a very  beautiful  net  of  ossific  wire-work. 
In  a circle,  t!ie  diameter  of  wliicli  is  half  an  incli,  we  see  a perfect  net  work,  resembling  a 
fine  lace  or  the  meslies  of  a spider’s  web.  Upon  this  first  layer  another  is  deposited,  and 
this  superimposed  net-work  of  bone  is  finer  than  the  first ; the  meshes  being  smaller  and  the 
bony  matter  more  abundant.  The  holes  of  the  second  net  arc  not  opposite  to  tliose  of  the 
first,  so  that  the  eye  no  longer  penetrates  the  bone,  although  the  structure  be  quite  light 
and  porous.  While  the  .second  and  third  layer  of  bone  is  deposited  on  the  outside  of  tlie 
first,  the  inner  layer  is  extending  in  threads  diver^ng  from  the  centre,  betwixt  which  deli- 
cate processes  of  bone,  intervening  ribs  are  formed  irregularly,  still  resembling  the  texture  of 
tlie  spider’s  web;  and  the  diverging  line  of  hone  being  tlie  stronger,  it  appears  as  if  the  cra- 
nial bones  formed  in  diverging  radii,  while  the  edge  of  the  bone  extends  in  fine  net  work, 
like  to  the  first  formed  speck  of  ossification. 

It  is  further  worthy  of  remark,  that  this  is  the  texture  of  true  hone,  and  that  what  are 
called  morbid  ossifications,  as  of  the  coats  of  arteries  and  other  membranes  are  merely  the 
deposite  of  earth, y matter  without  organic  structure.  C.  B. 

_ t The  proce.sses  apd  heads  are  named  the  epiphysis  an:l  apophysis  of  hones.  The  apophy- 
siss  a process  which  projects  from  the  bone  and  grows  from  it.  The  epiphysis  is  that  por- 
tion which  growing  by  a distinct  centre  of  ossification  is  afterwards  unitra  to  the  body  of 
tile  bone.  C.  B. 


AND  GROWTH  OF  BONES. 


16 


stretch  towards  either  end,  and  stop  there  (fig.  I.  plate  I.) ; 
then  it  begins  to  appear  that  the  heads  and  body  are  distinct 
parts ; the  fibres  of  the  growing  bone  have  extended  til)  the 
cartilage  is  annihilated,  and  only  a small  plate  remains,  separa- 
ting the  knobs  of  the  heads  from  the  long  body  of  the  bone. 
Thus  there  is  no  distinction  betwixt  the  heads  and  the  body, 
while  the  heads  are  cartiliginous ; they  begin  to  appear,  as 
distinct  parts,  at  that  stage  in  which  the  body  of  the  bone  is 
ossified,  and  each  of  the  heads  is  beginning  to  form  ; they  con- 
tinue three  distinct  bones,  during  all  the  early  part  of  life, 
and  are  easily  separated,  by  soaking  the  bone  in  water ; when 
they  are  separated,  there  is  seen  a rough  hollow,  on  the  sur- 
face of  the  epiphysis,  or  separated  head,  and  a rough  convexi- 
ty on  the  end  of  the  body : they  are  finally  united  into  one 
bone,  about  the  twentieth  year. 

In  die  original  cartilage,  there  is  no  hollow  nor  cavity  ; it  is 
all  one  solid  mass.  Fig.  1.  plate  II.  When  the  ossification 
first  appears,  the  cavity  of  the  bone  also  begins,  and  extends 
with  the  ossification  : at  first  the  cavity  is  confined  chiefly  to 
the  middle  of  the  bone,  and  extends  very  slowly  towards  the 
ends.  This  cavity,  in  the  centre  of  the  bone,  is  at  first  smooth, 
covered  with  an  internal  membrane,  containing  the  trunks  and 
branchings  of  the  nutritious  vessels,  which  enter  by  a great 
hole,  in  the  middle  of  the  bone ; and  the  cavity  is  traversed, 
with  divisions  of  its  lining  membrane,  which,  like  a net-work 
of  partitions,  conduct  its  branches  to  all  parts  of  the  interna] 
surface  of  the  bone;  and  its  nets,  or  meshes,  are  filled  witij  a 
reddish  and  serous  fluid  in  the  young  *bone,  but  secrete  and 
contain  a perfect  marrow  in  the  adult  bone. 

The  whole  substance  of  a bone  is  not  only  fibrous,  as  ap- 
pears outwardly,  but  is  truly  lamellated,  consisting  of  many 
distinct  and  delicate  plates  of  bone,  which  lie  over  each  other, 
in  regular  order,  and  might  suggest  the  notion  of  successive 
ossifications  of  the  periosteum  forming  the  bone.  These 
lamelliE,  or  plates,  are  more  condensed  and  firm,  towards  the 
outer  surface,  and  are  more  loose,  separate  and  spongy,  to- 
wards the  internal  surface  of  the  bone  ; and  it  is  easily  seen, 
during  the  growth  of  a young  bone,  that  the  inner  and  more 
delicate  plates  are  separating  from  the  walls  of  the  bone,  and 
receding  tow'ards  its  cavity  : and  these  plates,  being  again 
crossed  by  small  bony  partitions,  form  a net-work,  or  spengy 
mass,  w'hich  fills  the  whole  cavity  of  the  bone.  In  the  middle 
of  the  bone,  the  cavity  is  small,  the-  walls  thick,  and  having 
all  their  bony  plates  ; the  cells  of  net-work  few,  and  large  ; 
but  towards  the  ends,  the  bone  swells  out,  the  cavity  aKo  is 
large ; but  it  is  not  like  that  in  the  middle,  a large  tubular 


16 


OF  THE  FORMATION 


cavity  : it  is  so  crossed  with  lattice-work,  with  small  interstices 
and  cells,  that  it  seems  all  one  spongy  mass  of  bone  ; and  so 
many  of  the  inner  layers  are  separated,  to  form  this  profusion 
of  cells,  that  the  whole  substance  of  the  bone  has  degenerated 
into  this  lattice-work,  leaving  only  a thin  outward  shell.* 
Th  is  reticular  form  is  what  anatomists  call  the  cancelli, 
lattice-work,  net-work,  or  alveolar  part  of  the  bone  : it  is  all 
lined  with  one  delicate  membrane,  and  inward  partitions  of 
the  same  lining  membrane  cover  each  division  of  the  lattice- 
work,  forming  each  cell  into  a distinct  cavity.  In  these 
cavities,  or  cells,  the  marrow  is  secreted.  The  secretion  is 
thin  and  bloody  in  children  ; it  thickens  as  we  advance  in 
years ; it  is  a dense  oil,  or  marrow  in  the  adult.  The  mar- 
row is  firmer,  and  more  perfect  in  the  middle  of  the  bone, 
and  more  thin  and  serous  towards  the  spongy  ends.  The 
whole  mass,  when  shaken  out  of  the  bone,  is  like  a bunch  of 
grapes,  each  hanging  by  its  stalk.  The  globules,  when  seen 
with  the  microscope,  are  neat,  round,  and  white,  resembling 
small  pearls,  and  each  stalk  is  seen  to  be  a small  artery,  which 
comes  along  the  membrane  of  the  cancelli,  spreads  its 
branches  beautifully  on  the  surface  of  the  bag,  and  serves  to 
secrete  the  marrow,  each  small  twig  of  artery  filling  its  pecu- 
liar cell.  To  this,  an  old  anatomist  added,  that  they  had 
their  contractile  power,  like  the  urinary  bladder,  for  expel- 
ling their  contents ; that  they  squeezed  their  marrow,  by 
channels  of  communication,  through  and  among  the  bony 
layers ; and  that  their  (pi  exuded  into  the  joint,  by  nearly  the 
same  mechanism,  by  which  it  got  into  the  substance  of  the 
bone. 

White  the  constitution  of  a bone  was  not  at  all  understood, 
anatomists  noted  with  particular  care  every  trifling  peculiarity 
in  the  forms  or  connections  of  its  parts,  and  these  lamellae 
attracted  particular  notice.  That  a bone  is  formed  in  succes- 
sive plates,  is  easily  seen,  as  in  whalebone ; or  in  the  horns 
and  bones  of  the  larger  animals;  in  church-yard  bones, 
which  have  been  long  buried,  or  long  exposed  to  the  air. 
It  is  demonstrated  by  a careful  picking,  and  separation  of  the 
scales  in  a young  bone,  or  by  burning  a bone,  which  melts  and 
consumes  its  jelly,  and  leaves  the  bony  parts  entire.  It  is 
seen  in  the  common  diseases  of  bones ; for  they  cast  off  by 
successive  plates  or  leaves,  whence  the  process  is  named 
exfoliation ; and  one  plate  is  thoroughly  spoiled  and  cast  off, 

* That  it  is  merely  an  expansion  of  the  layers  wlrich  forms  the  cancelli,  and  a mere  swell- 
ing and  spnngiiies?  of  the  same  quantity  of  bony  substance,  which  makes  the  ends  so  mucii 
thicker  than  the  middle,  is  proved  by  this,  tliat  an  inch  of  the  smaller  bony  tube,  cut  from 
the  middle,  weighs  equally  with  an  inch  of  the  large  spongy  tube,  cut  out  from  the  ends. 


AND  GROWTH  OP  BONES. 


1? 


while  another  is  entire  and  sound.  Malphighi  had  first  ob- 
served the  lainellated  structure  of  bones,  likening  them  to  the 
leaves  of  a book.  Gagliardi,  who,  like  Hippocrates,  went 
among  the  burial  places  of  the  city,  to  observe  the  bones, 
there,  found  in  a tomb,  where  the  bones  had  been  long  ex- 
posed, a skull,  the  os  frontis  of  which  he  could  dissect  into 
many  layers,  with  the  point  of  a pin.*  He  afterwards  fou  .d 
various  bones,  from  all  parts  of  the  body,  thus  decomposed  ; 
and  he  added  to  the  doctrine  of  plates,  that  they  were  held 
together  by  minute  processes,  which,  going  from  plate  to 
plate,  performed  the  ofiSces  of  nails : these  appeared  to  his 
imagination  to  be  of  four  kinds,  straight  and  inclined  nails, 
crooked  or  hook-like,  an  I some  with  small  round  heads,  of 
the  forms  of  bolts  or  pins.f 

Another  notable  discovery,  was  the  use  of  the  holes  which 
are  very  easily  seen  througli  the  substance  of  bones,  and 
among  their  plates.  They  are,  indeed,  no  more  than  the 
ways  by  which  the  vessels  pass  into  the  bones ; but  the  older 
anatomists  imagined  them  to  be  still  more  important,  allow- 
ing the  matter  to  transude  through  all  the  substance  of  the 
bone,  and  keep  it  soft.  Now  this  notion  of  lubricating  the 
earthy  parts  of  a bone,  like  the  common  talk  of  fomentations 
to  the  internal  parts  of  the  body,  is  very  mechanical,  and 
very  ignorant;  for  the  internal  parts  of  the  body  are  both 
hot  and  moist  of  themselves,  and  neither  heat  nor  moisture 
can  reach  them  from  without  : the  bone  is  already  fully  wa- 
tered with  arteries ; it  is  moist  in  itself,  and  cannot  be  further 
moistened  nor  lubricated,  unless  by  a fuller  and  quicker  cir- 
culation of  its  blood.  It  must  be  preserved  by  that  moisture 
only  which  exists  in  its  substance,  and  must  depend  for  its 
consistence  upon  its  own  constitution;  upon  the  due  mixing 
up  of  its  gluten  and  earth.  Ever^  part  is  preserved  in  its  due 
consistence  by  the  vessels  which  form  its  subsistence ; and  I 
should  no  more  suppose  fat  necessary  for  preserving  the  moist- 
ness of  a bone,  than  for  preventing  brittleness  in  the  eye. — 

* Notwithstanding  what  is  here  delivered,  there  is  no  proof  of  the  bones  being  lanst  lla- 
ted  ; as  to  the  exfoliation  of  bone,  the  dead  [.ortion  is  more  generally  irregular  in  its  thick- 
ness, and  rngg^  on  its  inner  surface.  This  exfoliation  of  bone  is  a proce.«.s  of  tlie  living 
^ne,  and  the  inner  living  surface  recedes  from  the  outer  one,  because  tliat  outer  surface  is 
injured  or  dead.  The  nature  of  tlie  injury,  or  the  depth  to  which  the  bone  lias  become  dead, 
determines  the  extent  and  foim  of  the  [iortion  cast  off.  When  a scale  only  is  thrown  off, 
it  is  because  the  bone  is  only  dead  upon  the  surface  In  regard  to  the  breaking  up  of  the 
surface  of  the  cranial  hones,  when  they  lie  exposed,  the  .scales  are  similar  to  those  from 
atones  or  metals  ex(xised  to  the  influenee  of  the  air,  and  moisture,  and  varying  temperature: 
the  thickness  and  succession  of  exfoliations  depends  on  the  operation  of  the  weather,  not  ou 
the  original  formation  of  the  bone.  I have  never  seen  heat  produce  a lamellated  decompo- 
sition of  bone.  C.  B. 

+ These  nails  Gagiiardi  imagined  were  no  more  than  the  little  irregularities,  risings,  and 
hollows  of  the  adjoining  plates,  by  which  they  are  connected. 

VOL.  I.  C 


18 


OF  THE  FORMATION 


This  marrow  is,  perhaps,  more  an  accidental  deposition  than 
we,  at  first  sight,  believe.  We  indeed  find  in  it  such  a regu- 
larity of  structure,  as  seems  to  indicate  some  very  particular 
use  ; but  we  find  the  same  structure  exactly  in  the  common 
fat  of  the  body.  When,  as  we  advance  in  years,  more  fat  is 
deposited  in  the  omentum,  or  round  the  heart,  we  cannot 
entertain  the  absurd  notion,  of  fat  being  needed  in  our  old 
age,  to  lubricate  the  bowels  or  the  heart ; no  more  is  the  mar- 
row (which  is  not  found  in  the  child,)  accumulated  in  old  age, 
for  preventing  brittleness  of  the  bones.* 

The  blood  vessels  of  a bone  are  large,  in  proportion  to  the 
mass  of  the  bone.  For  first  one  great  trunk  enters  commonly 
about  the  middle  of  the  bone,  as  in  the  thigh-bone,  leg  or  arm, 
and  it  is  called  the  nutritious  or  medullary  artery  : it  goes  in 
the  central  cavity  of  the  bone,  spreads  upwards  and  down- 
wards, supplies  all  the  substance  of  the  bone  itself,  and  gives 
those  delicate  arteries  which  seci’ete  the  marrow.  Other  arte- 
ries enter  from  without  at  the  spongy  ends  of  the  bones,  where 
the  bones  are  not  visible  only,  but  very  large  in  the  adult ; par- 
ticularly large  arteries  enter  into  the  heads  of  the  holes,  as  of 
the  shoulder  or  of  the  thigh  bones ; and  there  the  periosteum 
adheres  very  strongly ; and  every  where  on  its  surface  the 
bone  is  supplied  by  numerous  vessels  from  the  periosteum  (and 
this  seems  indeed  to  be  the  chief  use  of  that  membrane  ;)  so  that 
in  tearing  off  the  periosteum,  the  surface  of  the  membrane, 
and  of  the  bone,  are  seen  covered  with  bloody  points  j all  the 
vessels  are  conducted  to  the  substance  of  the  bone  by  its  two 
membranes : the  internal  vessels  by  the  membrane  which  lines 
the  cavity,  and  which  is  known  b\  the  absurd  name  of  inter- 
nal periosteum  j the  external  one  by  the  outer  membrane,  the 
proper  or  external  periosteum. 

The  internal  periosteum  is  that  membrane  which  surrounds 
the  marrow,  and  in  the  bags  of  which  the  marrow  is  formed 
and  contained.  It  is  more  connected  with  the  fat  than  with 
the  bone ; and  in  animals,  can  be  drawn  out  entire  from  the 
cavity  of  the  bone  ; but  its  chief  use  is  to  conduct  the  vessels 
which  are  to  enter  into  the  substance  of  the  bone;  and  this  con- 
nection and  office  is  so  essential  to  the  life  and  health  of  the 
bone,  that  the  spina  ventosa,  or  scrophulous  bone,  is  merely  a 

* If  we  look  to  tlie  difference  there  is  in  the  adipose  membrane,  we  shall  find  it  more 
apparent  than  real.  The  fat  on  the  soles  of  the  feet  and  palms  of  the  hands  is  particularly 
firm,  but  this  firmness  results  from  the  strong  intertexture  of  filaments  of  a tendinous 
strength.  The  fat  in  the  exposed  parts  of  the  limbs  is  less  firm,  in  the  orbits  of  the  eyes 
more  delicate,  but  in  the  bones  it  lies  in  transparent  membranes,  and  is  quite  soft  and 
compressible.  The  difference,  however,  is  only  in  the  manner  in  which  the  bags  containing 
the  fat  are  bound  up  and  protected  ; where  the  substance  is  exposed  lo  pressure,  it  is  firm  j 
where  it  lies  concealed,  it  is  less  so ; but  where  it  is  altogether  within  the  iirotection  of  the 
bones,  tire  membranes  are  very  delicate,  and  the  fat  takes  the  appearance  of  marrow.  C.  B. 


AND  GROWTH  OF  BONES, 


19 


failure  of  the  internal  circulation,  a total  corruption  of  the  mar- 
row, and  a consequent  loss  of  the  medullary  vessels;  by 
which  the  whole  bone  dies,  is  thrown  out  by  nature,  or  oftener 
the  limb  must  be  cut  off,*  The  same  effect  is  produced  in 
otir  experiments,  where,  by  piercing  into  the  medullary  cavity, 
and  destroying  the  marrow,  the  shaft  of  the  bone  dies,  while 
the  heads  and  processes  live,  only  because  they  are  supplied 
more  fully  by  their  external  vessels. 

The  periosteum,  which  was  once  referred  to  the  dura  ma- 
ter, is  merely  condensed  cellular  substance  ; of  which  kind  of 
matter  we  now  trace  many  varied  forms  and-uses,  for  so  close 
is  the  connection  of  the  periosteum,  tendons,  ligaments,  fasciae, 
and  bursas,  and  so  much  are  these  parts  alike  in  their  nature 
and  properties,  that  we  reckon  them  but  as  varied  forms  of  one 
common  substance,  serving  for  various  uses  in  different  parts. 
The  periosteum  consists  ol  many  layers,  accumulated  and  con- 
densed one  above  another : it  adheres  to  the  body  of  the  bone 
by  small  points  or  processes,  which  dive  into  the  substance  of 
the  outer  layer,  giving  a firm  adhesion  to  it,  so  as  to  bear  the 
pulling  of  the  great  tendons,  which  are  fixed  rather  into  the 
periosteum  than  into  the  bone.  It  is  also  connected  with  the 
bone  by  innumerable  vessels.  The  layers  of  the  periosteum 
nearest  to  the  bone  are  condensed  and  strong,  and  take  a strong 
adhesion  to  the  bone,  that  the  vessels  may  be  transmitted  safe, 
and  the  fibres  of  this  inner  layer  follow  the  longitudinal  direc- 
tions of  the  bony  fibres.  The  periosteum  is  looser  in  its  tex- 
ture outwardly,  where  it  is  reticulated  and  lax,  changing  im- 
perceptibly into  the  common  cellular  substance.  There  the 
fibres  of  the  periosteum  assume  the  directions  of  the  muscles, 
tendons,  or  other  parts  which  run  over  it.  The  periosteum 
is  not  for  generating  bone  ; and  therefore  it  adheres  but  slight- 
ly to  the  growing  bone  : it  is  for  nourishing  the  external  plates ; 
and  therefore,  as  the  bone  grows,  and  as  the  external  plates 
are  further  removed  from  the  medi41ary  vessels,  the  adhesion 
of  the  periosteum  becomes  closer,  its  arteries  are  enlarged, 
and  the  dependence  of  the  outer  layers  on  the  periosteum  is 
as  well  proved  as  the  dependence  of  the  body  of  the  bone 
upon  its  medullary  artery ; for,  as  piercing  the  medulla  kills 
the  whole  bone,  hurting  the  periosteum  kills  the  outer  layers 
of  the  bone.  Any  accident  which  spoils  the  bone  of  its  pex’i- 
osteum  has  this  effect;  the  accidental  wounds  of  the  peri- 
osteum, deep  ulcers  of  the  soft  parts,  as  on  the  shin,  the  beat- 
ing of  aneurisms,  the  growth  of  tumours,  the  pressure  even  of 

* This  disease  is  rather  what  we  call  necrosis,  in  which  the  bone  dies.  _ The  spina  ven- 
tosa  is  the  consequence  of  abscess  in  the  cavifv  of  the  bone.  See  the  specihrens  in  ray  col- 
lection. C.  B. 


20 


OF  THE  FORMATIOI? 


any  external  body,  will,  by  hurting  the  periosteum,  cause  ex- 
foliation, which  is,  in  plain  terms,  the  death  of  the  external 
layer,  by  the  injury  of  the  outward  vessels ; and  an  active  in- 
flammation of  the  deeper  layers,  which  being  fully  nourished 
by  the  internal  arteries,  inflame,  swell,  become  porous  and 
spongy,  form  granulations,  and  these  granulations  push  olT  the 
mortified  plate,  and  form  themselves  into  new  bone,  which 
supplies  its  place.*' 

The  cartilages  are  also  a part  of  the  living  system  of  the 
bone  ; and  we  see  too  well,  in  the  question  of  the  bones  them- 
selves, how  unphilosophical  it  must  be  to  deny  organization 
and  feeling  to  any  part  of  the  living  body,  however  dead  or 
insulated  it  may  appear;  for  every  part  has  its  degree  of  life: 
the  eye,  the  skin,  the  flesh,  the  tendons,  and  the  bones,  have 
successive  degrees  of  feeling  and  circulation.  We  see,  that 
where  even  the  lowest  of  these,  the  bone,  is  deprived  of  its 
small  portion  of  life,  it  becomes  a foreign  body,  and  is  thrown 
off  from  the  healthy  parts,  as  a gangrened  limb  is  separated 
from  the  sound  body;  and  we  speak  as  familiarly  of  the  death 
of  a bone,  as  of  the  gangrene  of  soft  parts.  How,  then, 
should  we  deny  organization  and  life  to  the  cartilages.^  though 
surely,  in  respect  of  feeling,  they  must  stand  in  the  very  last 
degree. 

The  periosteum  goes  from  the  bone  over  the  surface  of  the 
cartilage  also,  where  it  is  named  perichondrium  : It  still  pre- 
serves its  own  vascular  nature;  the  vessels  can  be  injected; 
and  it  is  not  to  be  believed  that  the  perichondrium  has  these 
vessels,  without  communicating  them  to  the  cartilage  to  which 
it  belongs.  We  see  red  arteries  in  the  centre  of  an  ossifying 
cartilage,  and  therefore  we  know  that  the  trunk  of  the  artery 
may  be  red,  as  in  the  ossifying  part  of  the  cartilage,  and  yet 
the  extremity  of  the  same  artery  be  pellucid,  as  in  the  unossi- 
fied part.  Since  vessels  run  through  tiie  cartilage  to  generate 
bone,  we  cannot  in  reasonesuppose  that  these  vessels  are  pro- 
duced in  the  instant  in  which  they  appear : they  had  existed 
before  ; they  are  but  dilated  now ; the  increasing  action  di- 
lates them,  and  the  dilatation  makes  them  red  ; this  enables 
them  to  secrete  bone,  and,  in  many  cases,  as  in  the  accidental 
joint  formed  by  a fracture  ill  cared  for,  we  can,  by  paring  the 
cartilage,  set  the  vessels  free  again,  and  make  them  begin  to 
secrete.f 

* It  is  the  injury  to  the  surface  of  the  bone  which  causes  the  exfoliation,  not  the  loss  of 
vessels  by  tlie  separation  of  the  periosteum ; and  when  the  hone  dies,  as  in  necrosis,  Irom 
the  injury  to  the  marrow,  inflaraation  precedes  the  death.  C.  B. 

t This  is  true  as  a physiological  fact,  but  it  is  not  the  proper  method  of  curing  this  de- 
lict of  mrion  in  a bone.  Seetlie  2d  vol.  of  Operative  Surgery  by  Charles  Bell. 


AND  GROWTH  OF  BONES. 


21 


Wherever  we  find  a vascular  membrane  surrounding  and 
nourishing  any  part,  as  the  vitreous  or  crystalline  humours  in  the 
eye,  we  must  not  suppose  that  such  are  insulated  parts,  main- 
tained there  by  mere  adhesion ; but  must  consider  them  as 
parts  regularly  organized,  their  vascular  membrane  being  part 
of  their  living  system  ; and  though  the  transparent  humours  of 
the  eye,  the  cartilages  and  ligaments  over  all  the  body,  and 
all  the  system  of  the  bones,  have  been  considered  as  mere 
concretes,  and  insulated  parts,  they  are  now  known  lo  be 
regular  parts  of  the  living  whole.  The  cartilages  have  no  very 
active  circulation ; it  is  such  as  to  keep  them  in  life,  but  not 
so  active  as  to  endanger  inflammation,  in  the  continual  shocks 
which  they  must  endure  ; their  feeling  must  be  very  obscure, 
for  feeling  also  would  have  been  inconsistent  with  their  offices, 
which  is  to  cover  and  defend  the  bones;  to  yield  to  the  weight 
of  the  body,  and  to  restore  themselves  when  that  weight  is  re- 
moved ; to  bear  all  the  shocks  of  leaps  or  falls ; to  perform  all 
the  motions  of  the  body,  and  the  continual  workings  of  the 
joints,  where  they  rub,  and  even  crackle  upon  each  other  with- 
out danger  or  pain. 

We  now  understand  the  constitution  of  a bone,  and  can  com- 
pare it  fairly  with  the  soft  parts  in  vascularity,  and  in  feeling  j 
in  quickness  of  absorption ; in  the  regular  supply  of  blood 
necessary  to  the  life  of  the  bony  system  ; in  the  certain  death 
of  a bone,  when  deprived  of  blood  by  any  injury  of  its  marrow, 
or  of  its  periosteum,  as  a limb  dies  of  gangrene,  when  its  ar- 
teries are  cut  or  tied  ; in  the  continual  action  of  its  absorbents, 
forming  its  cavity,  shaping  its  processes  and  heads,  keeping 
it  sound  and  in  good  health,  and  regulating  the  degree  of  bo- 
ny matter,  that  the  cotnposition  may  neither  be  too  brittle  nor 
too  soft.  From  this  constitution  of  a bone,  we  could  easily 
foresee  how  the  callus  for  uniting  broken  bones  must  be  form- 
ed ; not  by  a mere  coagulation  of  extravasated  juice,  but  by  a 
new  organization  resembling  the  original  bone. 

The  priinordium  of  all  the  parts  of  the  body  is  a thin  gelati- 
nous mucus,  in  which  the  forms  of  the  parts  are  laid  ; and  the 
preparation  for  healing  wounds,  and  for  every  new  part  that 
needs  to  be  formed,  is  a secretion  of  mucus  which  is  soon  ani- 
mated by  vessels  coming  into  it  from  every  point.  In  every 
external  wound,  in  every  internal  inflammation,  wherever  ex- 
ternal parts  are  to  be  healed,  or  internal  viscera  are  about  to 
adhere,  a mucous  matter  is  secreted,  which  serves  as  a bed  or 
nidus,  in  which  the  vessels  spreatl  from  point  to  point,  till  the 
mucus  is  animalized  and  converted  into  a membrane : and 
thoB  the  heart,  the  intestines,  the  testicle,  and  other  part?,  ad- 


22 


OF  THE  FORMATION 


here  by  inflammation  to  the  coats  which  suiTound  them,  and 
which  are  naturally  loose.  It  is  a mucus  of  the  same  form 
which  unites  the  ends  of  a broken  bone;  and,  by  breaking  the 
bones  of  animals,  and  attending  to  the  progress  of  the  callus, 
we  find  first  a thin  mucus  ; then  that  thickened  into  a transpa- 
rent jelly ; that  jelly  growing  vascular,  and  these  vessels  gradu- 
ally depositing  nucleei  of  ossification  in  the  centre  of  the  mass ; 
and  by  madder  or  by  fine  injections,  we  can  make  the  jelly 
appear  vascular,  and  make  the  nuclsei  of  ossification  quite  red. 
The  colours  of  our  injections  begin  to  tinge  the  cartilage  as  it 
begins  to  ossify,  and  as  soon  as  the  ossification  is  general,  it 
receives  a general  tinge. 

When  we  find  the  substance  of  the  oldest  bone  thus  full  of 
vessels,  why  should  we  doubt  its  being  able,  from  its  own  pe- 
culiar vessels,  to  heal  a breach,  or  to  repair  any  loss  ''  We 
have  no  reason  to  refer  the  generation  of  callus  to  the  marrow, 
to  the  periosteum,  nor  to  the  substance  of  the  bone  itself,  for 
they  are  but  parts  of  the  common  system  of  a bone ; and  each 
part  of  this  system  is  of  itself  capable  of  regenerating  the 
whole.  How  little  the  constitution  of  a bone  has  been  under- 
stood, we  may  know  from  the  strange  debates  which  have 
subsisted  so  long  about  the  proper  organ  for  generating  callus- 
Some  have  pronounced  it  to  be  the  periosteum ; others,  the 
medullary  vessel,  and  internal  membrane  ; others,  the  substance 
of  the  bone  Itself : but  I have  been  employed  in  explaining, 
that  not  only  part  of  the  bone,  periosteum,  or  marrow,  but 
even  any  artery  in  all  the  system,  may  assume  that  action 
which  generates  bone  In  the  heat  of  this  dispute,  one  of  the 
most  eminent  anatomists  produced  a diseased  bone,  where  a 
new  bone  was  formed  surrounding  a carious  one,  and  the  spoil- 
ed bone  rattled  within  the  cavity  of  the  sound  one  : here  we 
should  have  been  ready  to  pronounce,  that  bone  could  be 
formed  by  the  periosteum  only.  But  presently  another  ana- 
tomist produced  the  very  reverse,  viz.  a sound  young  bone, 
forming  in  the  hollow  cylinder  of  a bone  which  had  been  long 
dead ; where,  of  course,  the  callous  matter  must  have  been 
poured  into  the  empty  cavity  of  the  spoiled  bone,  from  the 
ends  which  still  remain  sound,  or  must  have  been  secreted  by 
the  medullary  vessels.  But  the  truth  is,  that  callus  may  be 
thus  produced  from  any  part  of  the  system  of  a bone ; from 
its  periosteum,  from  its  medulla,  or  from  the  substance  of  the 
bone  itself.*  If  we  pierce  the  bone  of  any  animal,  and  de- 

* The  term,  system  of  a bone,  is  incorrect,  if  by  it  is  meant  the  periosteum  which  sur- 
rountls  the  bone,  and  the  marrow  within.  In  the  experiments  and  observations  which  I 
have  made,  neither  tile  periosteum  or  marrow  seemed  to  have  formed  the  bone ; and  1 con- 
clude, tlint  nothing  but  bone  can  form  hone,  by  the  continuation  of  natural  actions  ; and 
that  in  tlie  case  of  necrosis,  the  old  bone  inflames  and  begins  the  new  formation,  before  the 
continued  irritation  in  the  centre  kills  it.  C.  B. 


AND  GROWTH  OF  BONES. 


23 


sti’oy  the  marrow,  the  old  bone  dies,  and  a new  one  is  formed 
from  the  periosteum  : if  we  kill  the  creature  early,  we  find  the 
new  bone  to  be  a mere  secretion  from  the  inner  surface  of  the 
periosteum ; and  if  we  wait  the  completion  of  the  process,  we 
find  the  new  bone  beautiful,  white,  easily  injected,  and  thick, 
loose  in  its  texture,  and  vascular  and  bloody,  but  still  firm 
enough  for  the  animal  to  walk  upon ; and  in  the  heart  of  it, 
we  find  the  old  bone  dead  and  black.  If  we  reverse  this  ope- 
ration, and  destroy  the  periosteum  only,  leaving  the  nutritious 
vessels  entire,  then  the  new  bone  is  formed  fresh  and  vascular 
by  the  medullary  vessels,  and  the  old  one  quite  black  and  dead, 
surrounds  it  and  in  fractures  of  the  patella  or  knee-pan, 
where  there  are  no  medullary  vessels,  the  pieces  are  united  by 
a callus,  which  is  secreted  from  the  vessels  of  the  bone  itself. 

The  diseases  of  the  bones  are  the  most  frequent  in  surgery ; 
and  it  is  impossible  to  express  how  much  the  surgeon  is  con- 
cerned in  obtaining  true  ideas  of  the  structme,  constitution, 
and  diseases  of  bones ; how  tedious,  how  painful,  and  how 
loathsome  they  are  ; how  often  the  patient  must  lose  his  limb, 
or  endanger  his  life;  how  very  useful  art  is;  but  above  all, 
what  wonders  nature  daily  performs  in  recovering  bones  from 
their  diseased  state. 


* When  I injure  the  marrow  of  the  bone,  necrosis  is  the  consequence,  see  plate  Ilf. 
fig.  1.  1 divide  the  bone  of  its  periosteum  and  surround  it  with  a bit  of  bladder,  I 

find  the  whole  surface  exfoliates,  and  the  cavity  of  the  bone  fills  up  ; but  this  is  not  a con- 
sequence of  the  destruction  of  the  vessels  of  the  periosteum,but  of  the  contact  of  foreign  matter 
with  the  surface  of  the  bone.  An  effect  precisely  similar  is  the  consequence  cf  the  slough- 
ing of  the  soft  parts  over  a hone,  for  the  dead  slough  lying  on  the  surface  ofthe  bone  causes 
an  exfoliation. 

The  effect  of  injury  to  a living  bone  is  very  curious.  But  the  manner  in  which  the  hone 
resumes  its  pristine  form  is  still  more  worthy  of  obseiwation.  At  first  the  outward  exfolia- 
tion is  attended  with  a proportionate  filling  up  of  the  cavity  of  the  bone.  And  the  injury  to 
the  centre  and  body  of  the  bone  produces  a new  bone  around  the  old  one,  and  the  old  one 
at  last  dies  and  is  absorbed  or  discharged.  But  after  years  these  changes  are  again  reversed, 
and  the  new  hone  contracts  its  diameter,  and  the  cavity  becomes  of  its  narurai  dimentions, 
M that  the  evidence  of  the  clianges  which  the  bone  ha.s  undergoneare  quite  removed.  This 
is  a very  beautiful  example  of  the  influence  of  that  principle  which  coetiohs  t.be  growth  of  all 
the  parts  ofthe  body,  which  may  have  its  operation  deranged  by  violent  injuiy  or  by  disease ; 
but  which  will  at  last  by  slow  degrees  restore  the  part  to  its  natural  form  and  action.  C.  B. 


( 24  ) 


CHAP.  II. 

OP  THE  SKULL  IN  GENERAL THE  BONES  OF  WHICH  IT  IS 

COMPOSKU THMR  TABLES DIPLOE SUTURES THEIR 

ORIGINAL  UONOITION,  ANU  THEIR  PERFECT  FORM,  REPRE- 
SENTED AND  EXPLAINED. 

W illLE  the  bones  in  general  serve  as  a basis  for  the  soft 
parts,  and  supporting  and  directing  the  motions  of  the  body, 
cenain  bones  have  a higher  use  in  containing  those  organs 
whose  offices  are  the  most  essential  to  life  The  skull  de- 
fends the  brain ; the  ribs  and  sternum  defend  the  heart  and 
lungs ; the  spine  contains  that  prolongation  of  the  brain  which 
gives  out  nerves  to  all  the  body : and  the  injuries  of  each  of 
these  are  important  in  proportion  to  the  value  of  those  parts 
which  they  contain. 

How  much  tlie  student  is  interested  in  obtaining  a correct 
and  perfect  knowledge  of  the  skull,  he  must  learn  by  slow  de- 
grees. For  the  anatomy  of  the  skull  is  not  important  in  itself 
only  ; it  provides  for  a more  accurate  knowledge  of  the  brain  ; 
explains,  in  some  degree,  the  organs  oi  sense}  instructs  us  in 
all  those  accidents  of  the  head  which  are  so  often  fatal,  and  so 
often  require  the  boldest  of  all  our  operations.  The  marks 
which  we  take  of  the  skull,  record  the  entrance  of  arteries ; the 
exit  of  veins  and  nerves  ; the  places  and  uses  of  those  muscles 
which  move  the  jaws,  the  throat,  the  spine.  Indeed,  in  all 
the  human  body,  there  is  not  found  so  complicated  and  diffi- 
cult a study  as  this  anatomy  of  the  head;  and  if  this  fatiguing 
study  can  be  at  all  relieved,  it  must  be  by  first  establishing  a 
very  regular  and  orderly  demonstration  of  the  skull. 

For  this  end,  we  distinguish  the  face,  where  the  irregular, 
suriace  is  composed  of  many  small  bones,  from  the  cranium 
or  skull-cap,  where  a few  broad  and  fiat-shaped  bones  form 
the  covering  of  the  brain.  It  is  these  chiefly  which  inclose 
and  defend  the  brain,  which  are  exposed  to  injuries,  and  are 
the  subject  of  operation.  It  is  these  also  that  transmit  the 
nerves  : so  that  the  cranium  is  equally  the  object  of  attention 
with  the  anatomist  and  with  the  surgeon 

All  the  bones  of  the  cranium,  are  of  a flattened  form,  con- 
sisting of  two  tables,  and  an  intermediate  diploe,  which  an- 
swers to  the  cancelli  of  other  bones.  The  tables  of  the  skull 
are  two  flat  and  even  plates  of  bone  : the  external  is  tho  ight 
to  be  tuicker,  more  spongy,  less  easily  broken ; the  inner  tar 


OF  THE  SKULL  IN  GENERAL. 


25 


ble,  again,  is  dense,  thin,  and  brittle,  very  easily  broken,  and 
is  sometimes  fractured,  while  the  external  table  remains  en- 
tire : thence  it  is  named  tabula  vitrea,  or  the  glassy  table. 
These  tables  are  parted  from  each  other  by  the  distance  of  a 
few  lines  and  this  space  is  filled  up  with  the  diploe,  or  can- 
celli.  The  caneclli,  or  lattice-work,  is  a net  of  membranes, 
covered  with  vessels,  partly  for  secreting  marrow,  and  partly 
for  nourishing  the  bone  ; and  by  the  dura  mater  adhering  to 
the  internal  surface,  and  sending  in  arteries,  which  enter  into 
the  cancelli  by  passing  through  the  substance  of  the  bone,  and 
by  the  pericranium  covering  the  external  plate,  and  giving  ves- 
sels from  witliout,  which  also  enter  into  the  bone,  the  whole  is 
connected  into  one  system  of  vessels.  The  pericranium,  dura 
mater,  and  skull,  depend  so  entirely,  one  upon  the  other,  and 
are  so  fairly  parts  of  the  same  system  of  vessels,  that  an  injury 
of  the  pei’icranium  spoils  the  bone,  separates  the  dura  mater, 
and  causes  effusion  upon  the  brain : a separation  of  the  dura 
materis,  in  like  manner,  followed  by  separation  of  the  pericra- 
nium, which  had  been  sound  and  unhurt ; and  every  disease 
of  the  cancelli,  or  substance  of  the  bone,  is  communicated  both 
ways  ; inward  to  the  brain,  so  as^  to  occasion  very  imminent 
danger ; outwards  towards  the  integuments,  so  as  to  warn  us 
that  there  is  disease.  The  general  thickness  of  the  skull,  and 
the  natural  order  of  two  tables,  and  an  intermediate  diploe,  is 
very  regular  in  all  the  upper  parts  of  the  head.  In  perforating 
with  the  trepan,  we  first  cut  with  more  labour,  through  the  ex- 
ternal table  ; when  we  arrive  at  the  cancelli,  there  is  less  re- 
sistance, the  instrument  moves  with  ease,  there  is  a change  of 
sound,  and  blood  comes  from  the  tearing  of  these  vessels, 
which  run  in  the  cancelli,  betwixt  the  tables  of  the  skull.  Sur- 
geons thought  themselves  so  well  assured  of  these  marks,  that, 
it  became  a rule  to  cut  freely  and  quickly  through  the  outer 
table,  to  expect  the  change  of  sound,  and  the  flow  of  blood,  as 
marks  of  having  reached  the  cancelli,  and  then  to  cut  more 
deliberately  and  slowly  through  the  inner  table  of  the  skull. 
But  this  shows  an  indiscreet  hurry,  and  unpardonable  rashness 
in  operation.  The  patient,  during  this  sawing  of  the  skull,  is 
suffering  neither  danger  nor  pain  ;f  and  many  additional  rea- 
sons lead  us  to  refuse  altogether  this  rule  of  practice  : for  the 
skull  of  a child  consists  properly  of  one  table  only : or 
tables  are  not  yet  distinguished,  nor  the  cancelli  formed  : in 
youth,  the  skull  has  its  proper  arrangement  of  cancelli  and  ta- 

* In  anatomy,  there  is  occasion  in  almost  every  description,  for  a scale  of  smaller  parts. 
The  French  divide  their  inch  into  twelve  parts,  each  of  which  is  a line.  The  French  line, 
or  twelfth  of  an  inch,  is  a measure  which  1 shall  often  have  occasion  to  use. 

t There  is  a state  of  inflammation,  either  under  the  dead  bone  or  in  the  surrounding  bone, 
which  gives  extreme  pain,  eyen  when  the  silver  probe  touches  the  dead  bone.  C.  B. 

D 


26 


OP  THE  SKULL  IN  GENERAL. 


bles ; but  still,  with  such  irregularities,  and  exceptions,  as  make 
a hurried  operation  unsafe  : in  old  age,  the  skull  declines  to- 
wards its  original  condition, the  cancelli  are  obliterated,  the  ta- 
bles approach  each  other,  or  are  closed  and  condensed  into 
one  ; the  skull  becomes  irregularly  thick  at  some  points,  and  at 
others  thin,  or  almost  transparent ; so  that  there  can  hardly  be 
named  any  period  of  life  in  which  this  operation  may  be  per- 
formed quickly  and  safely  at  once.  But,  besides  this  gradual 
progress  of  a bone  increasing  in  thickness  and  regularity,  as 
life  advances,  and  growing  irregular  and  thinner  in  the  decline 
of  life,  we  find  dangerous  irregularities,  even  in  younger  skulls. 

There  are  often  at  uncertain  distances,  upon  the  internal  sur- 
face of  the  skull,  hollows  and  defects  of  the  internal  table, 
deep  pits,  or  foveas,  as  they  are  called,  produced,  perhaps,  by 
the  impressions  of  contorted  veins.  These  foveae  increase  in 
size  and  in  number,  as  we  decline  in  life  : they  are  more  fre- 
quent on  the  inner  surfaces  of  the  parietal  and  frontal  bones  j 
so  that  in  those  places  where  the  skull  should  be  most  regular, 
we  are  never  sure,  and  must,  even  in  the  safest  places,  perforate 
gradually  and  slowly. 

The  BONES  of  the  skull  are  divided  into  those  of  the 
cranium  ; the  bones  of  the  face ; and  common,  or  interme- 
diate bones.* 


* The  head  is  divided  into  the  cranium  and  face.  For  the  cranium  we  find  in  old  authors 
tlie  words  calva  or  calvaria  from  calvis,  hald,  or  sometimes  cerebri  galea,  as  being  like  a 
helmet  to  protect  the  brain. 

We-diid  some  terms  distinguishing  certain  parts  of  ttie  cranium  as  glabella,  the  smooth 
part  in  the  centre  and  lower  part  of  the  forehead.  Occiput,  the  ulmo.st  convexity  of  the 
head  backward.  Vertex,  the  crown  of  the  head  where  the  hairs  turn.  Bregma,  or  fon- 
tanelle,  which  are  terms  derived  from  very  false  notions,  but  which  mean  the  interstices  left 
in  a child’s  skull  betwixt  the  cranial  bones. 

The  student  ought  to  know  these  terms,  but  good  taste  rejects  them  even  from  medical 
language,  when  the  de.scription  can  he  given  in  plain  English. 

The  following  is  the  usual  division  of  the  bones  of  the  head. 

In  the  adult  head  there  are  thirty  bones  and  thirty-two  teeth. 


Of  the  Cranium, 
Six  Bones. 

1 Os  Frontis 

2 Ossa  Parietalia 
2 Ossa  Temporalia 
I Os  Occipitis 


Intermediate  or 
Common  Bones,  Two. 
1 Os  Sphenoides 
1 Os  Ethmoides 


Bones  of  the  Face, 
Fourteen. 

2 O.ssa  Maxillaria  Supra. 
2 Ossa  Malarum 
2 Ossa  Nasi 
2 Ossa  Palati 
2 O.ssa  Unguis 
2 Ossa  Turbinata  Infa- 
1 Vomer 

1 O.ssa  Maxillaria  Infe. 


Bones  of  the  Ear, 
Four  on  each  Side. 
Maleus 
Incus 

Os  Orbiculare 

Stapes 


Teeth,  Thirty-two. 

8 Incisorcs 
4 Cuspidati 
8 Bicuspideg 
12  Molares 


32 


OP  THE  SKULL  IN  GENERAL. 


27 


The  bones  of  which  the  cranium,  or  skull-cap  is  formed, 
are  eight  in  number.  1.  The  frontal-bone,  or  bone  of  the 
forehead,  forms  the  upper  and  fore  part  of  the  head, — extends 
a little  towards  the  temples,  and  forms  also  the  upper  part  of 
the  socket  for  the  eye.  2.  The  parietal  bones,  are  the  two 
large  and  flat  bones  which  form  all  the  sides,  and  upper  pari  of 
the  head  ; and  are  named  parietalia,  as  they  are  the  walls  or 
sides  of  the  cranium.  3.  The  os  occipitis,  is  named  from 
its  forming  all  the  occiput  or  back  of  the  head,  though  much 
of  this  bone  lies  in  the  neck,  and  is  hidden  in  the  basis  of  the 
skull.  4.  The  ossa  temporum  form  the  lower  parts  of  the 
sides  of  the  cranium  : they  are  called  temporal,  from  the  hair 
that  covers  them  being  the  first  to  turn  grey,  marking  the  time 
of  life.  5.  The  os  3:thmoides,  and,  6.  the  os  sphenoioes, 
are  quite  hidden  in  the  basis  of  the  skull : they  are  very  irre- 
gular and  very  difiicultly  described  or  e^xplained.  The  os  mtu- 
MOiuEs,  is  a .'fmall  square  bone,  hollow,  and  with  many  cells 
in  it ; it  hangs  over  the  nose,  and  constitutes  a great  and  im- 
portant part  of  that  organ,  and  at  the  same  time  supports  the 
brain.  The  olfactory  nerves,  by  passing  through  it  at 
many  points,  perforate  it  like  a sieve ; and  it  takes  its  name 
from  this  perforated  or  athraoid  plate.  The  os  sphenoides 
is  larger  and  more  irregular  still ; placed  further  back ; locked 
in  betwixt  the  occipital  and  sethmoidal  bones ; lies  over  the 
top  of  the  throat,  so  that  its  processes  form  the  back  of  the 
nostrils,  and  roof  of  the  mouth  ; and  it  is  so  placed,  as  to  sup- 
port the  very  centre  of  the  brain,  and  transmit  almost  all  its 
nerves. 

SUTURES. — All  these  bones  are  joined  together  by  seams, 
which,  from  their  indented,  or  dove-tailed  appearance,  are  na- 
med sutures.* 

* Suture  is  a common  term  for  the  line  of  contact  of  tlie  flat  hones.  It  is  a form  of  union 
admitting  of  no  motion,  and  is  somewhat  varied  according  to  to  the  degree  of  pressure  they 
have  to  sustain  They  may  be  arranged  thus ; 

JUNCTURA  ImMOBILTS. 

1.  Sulurn  Vera — Serrata. — Dentata. 

2.  Sutura  Spuria  — Linea — Harmonia. 

3.  Sutura  Squarrmsa. — Limbosa. 

4 Gamphosis. 

Monro  [Jmtrmiy  of  the  Human  Bones)  expresses  the  common  opinion,  that  “ the  suture 
“ is  formed  by  the  two  bones  meeting  while  they  are  tims  flexible  and  yielding,  and  have 
“ not  yet  come  to  their  full  extent  of  growth,  so  that  they  mutually  force  into  the  inter- 
“ slices  of  each  other,  till  meeting  with  such  resistance  as  they  are  not  able  to  overcome 
“ they  are  stopt  from  sprouting  out  further  or  are  reflected,  &c.”  1 object  to  this,  because 
St  represents  the  suture  to  be  an  accident.  Are  not  all  Imnes  pushrf  together  as  here 
described  f yet  the  true  suture  is  not  universal. 

It  is  acknowledged,  that  there  is  an  object  and  intention  in  having  the  bones  of  the  child’s 
head  in  separate  pieces.  The  cons^uence  of  this  is,  that  sutures  are  formed  when  their 
Jnargins  unite  But  why  is  there  this  variety  in  the  form  of  the  juncture  Certainly  this 
is  not  accidental.  We  must  notice  that  when  a hone  is  light  and  weak  it  is  united  by  the 
simple  line  of  contact,  or  what  !.■'  called  by  harmonia.  On  the  contrary,  where  the  bone  has 
to  bear  pressure,  or  where  it  has  a more  important  organ  to  protect,  it  is  thick  and  firm 


28 


OF  THE  SKULL  IN  GENERAL. 


1.  The  CORONAL  SUTURE,  IS  that  whlcli  joins  the  frontal  to 
the  parietal  bones ; extends  almost  directly  across  the  head, 
from  ear  to  ear ; descends  behind  the  eye,  into  the  deep  part 
of  the  temple  ; and  there  loosing  its  serrated  appearance,  be-, 
comes  like  the  squamous  or  scaly  suture,  which  joins  the  tem- 
poral bones.  It  is  named  coronal,  because  the  ancients  wore 
their  garlands  on  this  part  of  the  head.  But  the  suture  had 
been  better  entitled  to  this  name,  had  it  surrounded  the  head, 
than  as  it  crosses  it. 

2.  The  LAMBJ)ou)AL  SUTURE,  is  that  One  which  joins  the  pa- 
rietals  to  the  occipital  bone.  It  begins  behind  one  ear,  ascends 
and  arches  over  the  occiput,  and  descends  behind  the  other 
ear.  It  thus  strides  over  the  occiput,  in  a form  somewhat  re- 
sembling the  letter  lambda  (A),  of  the  Greeks,  whence  its 
name. 

3.  The  SAGITTAL  SUTURE,  joins  the  parietal  bones  to  each 
other ; runs  on  the  very  top  of  the  head  ; extends  forwards 
from  the  lambdoid  suture  till  it  touches,  or  sometimes  passes, 
the  coronal  suture  ; and  from  lying  betwixt  these  two  sutures, 
like  an  arrov/  betwixt  the  string  and  the  bow,  it  has  been 
named  sagittal. 

4.  The  TEMPORAL  SUTURES,  join  the  temporal  bones  to  the 
parietal,  occipital,  and  frontal  bones ; the  sphenoid  bone  also 
enters  into  the  temporal  suture,  just  behind  the  eye.  The 
temporal  suture  makes  an  arch  corresponding  almost  with  the 
arch  of  the  external  ear  ; it  meets  the  coronal  suture  an  inch 
before  the  ear,  and  the  lambdoidal  an  inch  behind  it.  This 
back  part  belongs  as  much  to  the  occipital  as  to  the  temporal 
bone ; and  so  has  been  named  sometimes,  additamentum  su- 
turge  lambdoidalis  ; sometimes  additamentum  suturae  squamo- 
sae  : for  this  temporal  suture  is,  on  account  of  the  edge  of  the 
temporal  and  occipital  bones  being  tbin,  and  like  scales  of  ar- 
mour laid  over  each  other,  often  named  the  squamous  or  scaly 
suture. 

5.  The  SPHENOIDAL  and  ethmoidal  sutures,  are  those 
which  surround  the  many  irregular  processes  of  these  two 
bones,  and  join  them  to  each  other  and  to  the  rest. 

I'iidit  is  joined  by  the  indented  suture,  which  is  a union  by  a more  perfect  mcclianisin,  and 
gives  strength  proportioned  to  the  bone.  Thus  we  see  that  the  bones  of  the  cranium  are 
united  by  the  true  suture.  But  the  most  perfect  specimen  of  the  tiue  suture  will  be  found 
ill  the  skulls  of  horned  cattle,  because  tliis  instrument  of  defence  must  be  reared  on  a firm 
foundation. 

Further,  the  anatomist  repeats  from  day  to  day  and  year  to  year,  that  the  squamous  su- 
ture is  made  by  the  pressure  of  the  temporal  muscle ; an  accident  again.  No ; it  is  formed 
lor  a purpose,  it  is  the  kind  of  suture  the  best  calculated  to  bind  in  the  ci-anial  bones,  and_ 
to  prevent  the  starling  of  the  parietal  bones.  He  does  not  contemplate  the  structure  of 
the  body  in  a proper  temper  of  mind,  who  looks  upon  these  adaiirablc  provisions  as  the  effect 
of  accident.  C.  B. 


OF  THE  SKULL  IN  GENERAL. 


29 


6.  The  TRANSVERSE  SUTURE,  is  One  which,  running  across 
the  face,  and  sinking  down  into  the  orbits,  joins  the  bones  of 
the  skull  to  the  bones  of  the  face ; but  with  so  many  irregula- 
rities and  interruptions,  that  the  student  will  hardly  recognize 
this  as  a suture. 

7.  The  ZYGOMATIC  SUTURE,  is  one  which  joins  a branch  of 
the  temporal  bone,  to  a process  of  the  cheek  bone ; forming 
an  arch,  zygoma,  or  yoke  ; but  this  suture  has  no  extent,  it  is 
a serrated  appearance  at  one  single  point  only. 

To  mark  and  know  these  sutures,  and  to  be  able  to  trace 
them  in  imagination,  upon  the  naked  head,  to  foresee  where  a 
suture  will  present,  and  how  far  it  runs,  may  be  a matter  of 
great  importance  to  the  surgeon.  Hippocrates,  who  has  had 
more  to  praise  his  honesty  than  to  follow  his  example,  ac- 
knowledges his  having  mistaken  a suture  for  a fracture  of  the 
skull ; and  since  this  warning,  various  contrivances  and  marks 
have  been  thought  of,  for  preventing  the  like  mistake.  It 
may  be  useful  to  remember  that  the  suture  has  its  serr:u  or  in- 
dentations, is  firmly  covered  by  the  pericranium,  is  close,  and 
does  not  bleed : but  that  a fissure,  or  fracture  of  the  skull, 
runs  in  one  direct  line,  is  larger  and  broader  at  the  place  of 
the  injury,  and  grows  smaller  as  you  recede  from  that,  till  it 
vanishes  by  its  smallness ; and  that  it  always  bleeds.  Indeed, 
the  older  surgeons,  observing  this,  poured  ink  upon  the  sus- 
pected part,  which,  if  the  skull  was  hurt,  sunk  into  the  fissure, 
and  made  it  black  and  visible  ; but  left  the  suture  untouched. 
They  also  directed  to  make  the  patient  take  a wire  betwixt 
his  teeth,  which  being  struck  like  the  string  of  an  instrument, 
he  would  feel  the  twang  produce  a painful  and  particular  sen- 
sation in  the  fractured  part  of  the  head.  But  after  all  these 
observations,  in  place  of  any  true  and  certain  marks,  we  find 
a number  of  accidents  w'hich  may  lead  us  into  a mistake. 

Sutures  cannot  be  distinguished  by  their  serrse  or  teeth,  for 
the  temporal  sutures  want  this  common  character,  and  rather 
resemble  capillary  fractures  of  the  skull  nor  even  by  their 
places,  for  we  know  that  there  are  often  insulated  bones  (ossa 
Wormiana)  surrounded  with  peculiar  joinings,  which  so  de- 
range the  course  of  the  common  sutures,  that  the  joinings 
may  be  mistaken  for  fractures  of  the  skull,  and  the  ossa  Wor- 
miana for  broken  parts.  Sometimes  the  squamous  suture  is 
double,  with  a large  arch  of  bone  intercepted  betwixt  the  true 
and  the  false  suture  ; or  the  sagittal  suture,  descending  beyond 
its  usual  extent,  and  quite  to  the  nose,  has  been  mistaken  for  a 
fracture,  and  trepanned ; and  oftener  in  older  skulls,  the  su- 


* Viz.  Fractures  as  small  as  a hair,  thence  named  capillary. 


30 


OF  THE  SKULL  IN  GENERAL. 


tures  are  entirely  obliterated,  all  over  the  head.  If  the  sur- 
geon should  pour  ink  upon  the  skull,  he  would  have  reason  to 
be  ashamed  of  an  experiment  so  awkward  and  unsuccessful ; 
and  for  the  old  contrivance  of  a wire  or  cord  held  in  the 
mouth,  it  cannot  be  done,  since  the  patient  is  commonly  in- 
sensible ; and  even,  though  less  hurt,  his  feelings,  after  such 
an  accident,  must  be  very  confused ; he  must  be  too  liable  to 
be  deceived  : and  we  cannot  on  such  slender  evidence  as  this, 
perform  so  cruel  an  operation  as  cutting  up  the  scalp,  or  so 
dangerous  a one  as  the  trepan. 

For  various  reasons,  we  are  careful  to  trace  the  bones  from 
their  original  soft  and  gristly  state,  to  their  perfect  condition  of 
hard  bone  : and  most  of  all,  we  are  concerned  to  do  so  in  the 
head,  where,  in  childhood  the  appearances  are  not  singular 
and  curious  only,  but  have  always  been  supposed  to  indicate 
some  wise  and  useful  purpose.  It  is  in  this  original  condition 
of  the  soft  and  growing  bones,  that  anatomists  have  sought  to 
find  a theory  of  the  sutures,  how  they  are  formed,  and  for 
what  uses.  It  has  been  remarked,  that  the  number  of  pieces 
in  the  skull,  is  infinitely  greater  in  the  child  than  in  the  man. 
These  bones  ossifying  from  their  centi’e  towards  their  circum- 
ference, it  happens,  of  course,  that  the  fibres  are  close  at  the 
centre  of  ossification,  and  are  more  scattered  at  the  extremities 
of  the  bone  : when  these  scattered  fibres  of  opposite  bones 
meet,  the  growing  fibres  of  one  bone  shoot  into  the  interstices 
of  that  which  is  opposed  : the  fibres  still  push  onwards,  till 
they  are  stopped  at  last,  and  the  perfect  suture,  or  serrated  line 
of  union  is  formed. 

In  dilating  this  proposition,  we  should  observe,  that  in  the 
boy,  all  the  bones  in  the  head  are  membranous  and  imperfect. 
The  membranous  interstices  begin  to  be  obliterated  ; the 
sutures  are  beginning  to  close  ; the  distinction  of  two  tables  is 
not  yet  established ; the  cancelli  are  not  yet  interposed  be- 
tween the  plates,  the  sinuses,  or  caverns  of  the  bones,  as  in 
the  forehead,  the  nose,  and  the  jaw,  are  not  formed  ; and  each 
bone  is  not  only  incomplete  towards  its  edges  and  sutures,  but 
consists  often  of  many  parts.  The  os  frontis  is  formed  of 
two  pieces,  which  meet  by  a membranous  union  in  the  middle 
of  the  bone.  The  ossa  farietalia  have  one  great  and  promi- 
nent point  of  ossification  in  the  very  centre  of  each,  from 
which  diverging  rays  of  ossification  extend  towaids  the  edges 
of  the  bone.  The  os  occipitis  is  formed  in  four  distinct 
pieces : and  the  temporal  bones  are  so  fairly  divided  into 
two,  that  their  parts  retain  in  the  adult  the  distinct  names  of 
petrous  and  squamous  bones.  Although  these  are  all  the 
regular  points  of  ossification,  yet  sometimes  there  occur  small 


OF  THE  SKULL  IN  GENERAL. 


31 


and  distinct  points,  which  form  irregular  bones,  uncertain  in 
number  or  size,  found  chiefly  in  the  lambdoid  suture,  some- 
times numerous  and  small,  more  commonly  they  are  few  in 
number,  and  sometimes  of  the  full  size  of  a crown,  always 
distorting  more  or  less  the  course  of  the  suture,  and  being  thus 
a subject  of  caution  to  the  surgeon  : these  are  named  ossa 
TK1Q.UKTKA,  Or  Tiu angularia,  from  their  angular  shape,  or, 
woKMiANA,  from  Olaus  Worrai^is,  who  remarked  them  first. 
Now  the  os  frontis  being  formed  into  two  larger  pieces,  their 
edges  meet  early  in  life,  and  they  form  a suture  ; but  the 
bones  continuing  to  grow,  their  opposite  points  force  deeper 
and  deeper  into  each  other,  till  at  last  the  suture  is  entirely 
obliterated,  and  the  bones  unite ; and  so  this  suture  is  found 
always  in  the  child,  seldom  in  the  adult,  almost  never  in  old 
age.  The  occipital  bone  having  four  points,  they  are  closer 
upon  each  other,  they  meet  early,  are  soon  united  j and,  al- 
though very  distinct  in  the  child,  no  middle  suture  has  ever 
been  found  in  the  adult,  but  always  the  four  pieces  are  united 
into  one  firm  and  perfect  bone.  The  parietal  bones  have  their 
rays  most  of  all  scattered  ; the  rays  of  ossification  run  out  to  a 
great  distance,  and  diverge  from  one  single  point,  so  that  at 
their  edges  they  are  extremely  loose,  and  they  never  fail  to 
form  sutures,  by  admitting  into  their  interstices  the  points  and 
edges  of  the  adjoining  bones.  The  surest  and  most  constant 
sutures  are  those  formed  by  the  edges  of  the  parietal  bones; 
the  sagittal  in  the  middle,  the  coronal  over  the  forehead,  the 
lambdoidal  behind,  and  the  squamous  suture,  formed  by  their 
lower  edges.  But  another  phenomenon  results  at  the  same 
time,  from  this  meeting  and  opposition  of  the  fibres  and  inter- 
stices of  the  growing  bones  : that  when  the  opposite  fibres 
meet  too  early,  they  are  not  fairly  admitted  into  the  open 
spaces  of  the  opposite  bone  ; but  the  fibres  of  each  bone  being 
directly  opposed  point  to  point,  they  both  turn  inwards,  and 
form  a ridge  or  spine,  such  as  is  seen  on  the  inner  surfaces  of 
the  frontal  and  occipital  bones.  Such  is  the  common  theory, 
which  I suspect  is  imperfect,  and  wliich  should  be  received 
with  some  reserve,  for  all  the  phenomena  are  not  yet  explain- 
ed; we  find  each  suture  always  in  its  appointed  place  ; we 
find  nothing  like  a suture  formed  betwixt  the  head  and  body 
of  a long  bone,  though  they  are  formed  in  distinct  points,  and 
are  not  united  till  after  the  years  of  manhood ; we  find  no 
sutures  when  bones  are  broken  and  reunited,  when  they  have 
been  spoiled  and  are  replaced,  when  a piece  of  spoiled  bone 
has  been  cut  away,  nor  when  a new  shaft  of  a bone  is  formed 
by  the  secreting  vessels,  and  is  united  to  the  heads  of  the  old 
bone.  These  are  accidents  which  hold  us  at  least  in  doubt. 


32  OF  THE  SKULL  IM  GENERAL. 

It  has  been  supposed,  and  with  much  appearance  of  truth, 
that  the  sutures  limit  the  extent  of  fractures,  leave  a free  com- 
munication of  the  internal  with  the  external  parts ; that  they 
must  serve  as  drains  from  the  brain  ; that  they  are  even  capa- 
ble of  opening  at  times,  so  as  to  give  relief  and  ease  in  the 
most  dreadful  diseases  of  the  head.  But  I fear  we  are  not  yet 
able  to  see  the  meaning  of  this  peculiarity  of  structure  ; for 
the  sutures  are  regular  and  uniform  to  a wonderful  degree, 
while  these  uses  of  them  are  far  from  being  proved. 

The  sutures  surely  were  not  intended  by  nature  for  limiting 
the  extent  of  fractures ; for  fractures  traverse  the  skull  in  all 
directions  ; cross  the  sutures  with  ease  ; and  very  often,  pas- 
sing all  the  sutures,  they  descend  quite  to  the  basis  of  the 
skull,  where  we  dare  not  follow  them  with  the  knife,  nor  ap- 
ply the  trepan.  Indeed  we  do  not  even  know  that  limiting  the 
extent  of  factures  could  be  a gracious  provision  of  nature,  since 
it  would  rather  appear  by  the  common  accidents,  that  the 
more  easily  the  b-one  yields,  the  less  is  the  injury  to  the  brain; 
and  that  where  the  fracture  is  wide  and  large,  the  symptoms 
are  milder,  and  the  danger  less. 

Neither  were  they  intended  as  drains;  for  surely  it  is  a bold 
position  to  assume,  that  nature  has  carefully  provided  for  our 
making  issues  upon  the  sutures.  When  the  original  openness 
of  the  head  and  the  membranous  condition  of  the  sutures  was 
first  observed,  it  was  thought  to  be  an  observation  of  no  small 
importance.  The  ancients  believed  that  the  membranes  of 
the  brain  came  out  by  the  sutures,  to  form  the  pericranium, 
and  going  from  that  over  the  several  joints,  formed  the  peri- 
osteum for  all  the  bones.  They  saw  a close  connection  betwixt 
the  external  and  internal  membranes  of  the  skull,  and  they 
thought  that  nature  had  intended  there  a freer  communication, 
and  an  occasional  drain.  They  found  the  sutures  particularly 
wide  and  membranous  in  a child,  which  they  attributed  to  the 
watery  state  of  its  brain,  requiring  a freer  outlet  than  in  the 
adult ; and  accordingly  they  named  the  opening  of  the  child’s 
head  the  the  bregma,  fons,  fontanelle,  the  fountain,  by  which 
they  believed  there  was  a continual  exudation  of  moisture 
from  the  brain. 

We  might  have  expected  these  notions  to  have  vanished 
with  the  doctrines  of  humours  and  revulsion  which  gave  rise 
to  them  ; but  both  the  doctrines  and  the  practice,  have  been 
revived  of  late  years;  and  a surgeon  of  some  eminence  has 
been  at  pains  to  examine  various  skulls,  trying  to  find  which 
of  all  the  sutures  remains  longest  open,  and  which  should  form 
the  readiest  and  surest  drain  ; and  after  a curious  examination 
of  each,  he  decidedly  condemns  the  fontanelle  ; finds  the  ad- 


OP  THE  SKULL  IN  GENERAL. 


33 


ditamentura  of  the  squamous  suture  always  open,  and  expects 
this  superior  advantage  from  placing  his  issues  there,  that  he 
will  command  at  once  a drain  both  from  the  cerebellum  and 
from  the  brain.  But  these  notions  of  derivation  and  revulsion, 
of  serous  humours  falling  upon  the  brain,  of  drains  of  pituita 
by  the  nose,  and  through  the  sutures,  were  much  cherished 
by  the  ancients,  had  been  long  forgotten,  and  have  not  been 
effectually  revived  by  this  attempt. 

It  cannot  be  denied,  that,  in  some  instances,  the  sutures 
have  continued  quite  open  in  those  grown  in  years,  or  have 
opened  after  a most  wonderful  manner,  in  some  diseases  of 
the  head. 

A young  man  having  been  brought  into  an  hospital  ill  of  a 
fever,  the  physicians  observed  with  surprise,  a very  strong  pul- 
sation behind  the  ear:  upon  applying  the  finger,  a strong  beat- 
ing was  felt ; the  part  was  soft  and  yielding ; and  upon  open- 
ing his  head,  after  death,  there  was  found  a large  membra- 
nous space.  Diemorbrock  found  the  fontanelle  open  in  a 
woman  of  forty  years  of  age.  Bauhin  says,  that  in  his  own  wife, 
twenty-six  years  of  age,  the  sutures  were  not  yet  closed. 

This  fontanelle,  or  opening  at  the  meeting  of  the  coronal 
and  sagittal  sutures,  was  once  thought  to  be  a sure  mark  for  the 
accoucheur  to  judge  by,  both  of  the  life  of  the  child,  and  of 
the  direction  in  which  its  head  presents.  It  is  large  and  soft 
in  a child,  and  the  good  women  lay  a piece  of  firm  cloth  upon 
it,  and  defend  it  with  particular  care-  It  begins  to  contract 
from  the  time  of  birth ; and  in  the  second  and  third  year,  it 
is  entirely  closed.  Its  closing  is  delayed  by  weakness,  scro- 
phulous  complaints,  and  indeed  by  any  lingering  disease ; it 
closes  very  late  in  rickets,  and  in  hydrocephalic  children  the 
bones  never  close,  but  continue  soft,  yield  to  the  watery  swell- 
ing of  the  brain,  and  separate  in  a wonderful  degree,  so  as  to 
hold  ten  or  twelve  pounds. 

As  the  sutures  continue  open  in  a hydrocephalic  child,  they 
are  said  to  open  again  in  the  few  in.:tances  where  adults  are 
seized  with  the  same  disease.  We  are  told  that  it  opens  in 
those  dreadful  head-aches  which  are  sometimes  fatal,  and  that 
the  celebrated  Paschal  having  died  after  terrible  torments,  was 
found  to  have  the  sutures  opened  again  : it  is  even  said  that 
they  open  during  disease,  and  close  after  the  cure.  “ That 
“ a man  of  forty  years  of  age,  being,  in  the  dog-days,  seized 
“ with  a raging  fever,  delirium,  watching,  and  dreadful  pains 
“ of  the  head,  his  sutures  opened  on  the  seventh  day,  were 
“ a^  wide  as  in  a child,  n&t  only  so  as  to  be  distinguished  by 
“ the  finger,  but  that  the  attendants  could  see  the  pulsations 
“ of  the  brain ; the  fever,  after  some  time,  abated ; the 

E 


34 


OF  THE  SKULL  IN  GENERAL. 


“ pains  ceased;  the  sutures  closed,  and  this  man  lived  many 
“ years  in  perfect  health.”  So  Hildanus  reports  the  case, 
and  he  also  says,  in  another  instance,  that  the  sutures  had  part- 
ed in  a violent  hemicrania,  with  an  audible  noise. 

Yet  if  this  were  a regular  design  of  nature,  the  relief  should 
be  perfect ; perhaps  the  opening  of  the  sutures  should  be 
more  easy,  and  the  accident  almost  as  common  as  diseases  of 
the  head  ; or  perhaps  it  bad  been  the  more  merciful  order,  to 
have  determined  a quick  and  sudden  period  for  such  dreadful 
and  incurable  diseases  as  these. 

The  sutures  of  the  cranium  are  accidental  merely,  and  of 
little  use.  The  result,  perhaps,  of  this  well  known  law,  that 
nature  seeks  to  facilitate  ossification,  by  beginning  the  process 
in  many  points  ; and  she  establishes  as  many  distinct  points  in 
healing  a broken  limb  as  in  forming  the  skull.  But  however 
they  may  be  formed,  their  uses  cannot  be  of  that  importance 
which  has  been  supposed  ; for  there  are  twenty  separate  bones, 
and  twenty  sutures  in  the  face,  where  they  can  neither  stop 
fractures,  nor  serve  as  drains,  nor  open  so  as  to  give  relief. 

But  if  the  sutures  of  the  cranium  have  any  thing  peculiar  and 
different  from  those  of  the  face,  in  that,  perhaps,  their  pecu- 
liar uses  may  be  found.  We  cannot  pass  unnoticed  their  loose- 
ness and  flexibility  in  the  new-born  child ; how  wonderfully 
the  head  of  the  child  is  increased  in  length,  and  reduced  in 
breadth  in  the  time  of  delivery,  and  how  much  this  conduces 
to  an  easy  and  happy  labour. 

The  most  eminent  anatomists  have  condescended  to  remark, 
that  in  the  various  nations  of  Europe,  the  head  has  various 
forms,  which  they  ascribe  to  so  slight  a pressure  as  that  which 
dress,  or  even  the  posture  of  the  head  might  produce.  But 
how  very  far  Vesalius  was  deceived  in  calculating  thus,  is  easi- 
ly proved.  The  Turks,  says  he,  have  their  heads  flattened 
by  wearing  the  turban.  But  the  turban  is  an  eastern  dress : 
the  Turks  or  Tartars  are  a northern  people,  who  assume  this 
dress  only  when  conquest  brings  them  into  a W'armer  climate, 
and  the  prominent  cheek-bones,  parted  eyes,  and  flat  heads, 
continue  in  the  Tartars,  who  have  but  newly  assumed  the  tur- 
ban, while  the  conquered  nations  which  have  worn  it  long,  are 
distinguished  by  their  regular  and  beautiful  features.  Perhaps 
by  contrivance  and  force,  we  may  distort  the  head  of  a child ; 
and  we  may  almost  believe  what  is  told  of  the  negroes  of  the 
Caribbee  islands,  who  had  contrived,  by  pressure,  to  flatten 
their  children’s  heads,  that  their  race  might  be  in  future  distin- 
guished from  those  who  had  submitted  to  the,  Spanish  yoke; 
or  of  what  is  told  so  often  of  eastern  nations,  i r'  .,  Srey  some- 
times mould  the  heads  of  children  into  monstrous  and  uncouth 


OF  THE  SKULL  IN  GENERAL. 


35 


librms,  to  extort  charity,  or  as  an  act  of  religion.  Were  I to 
assign  a reason  for  the  flexible  bones,  and  wide  sutures,  and 
the  yielding  condition  of  the  head  of  the  child,  I should  say 
that  it  were  meant  hy  nature  to  stand  in  the  place  of  that  se- 
paration of  the  bones  of  the  pelvis  which  has  been  supposed, 
but  which  cannot  exist ; for  the  child’s  head  is  moulded  with 
little  injury,  is  evolved  again  without  help ; and  it  seems  a 
provision  of  nature,  since  the  child  scarcely  feels  the  change: 
but  no  woman  has  been  known  to  have  the  joinings  of  the  pel- 
vis relaxed  or  dissolved  without  pain  and  danger,  confinement 
for  many  months,  a temporary  lameness,  and  sometimes  she 
is  rendered  unable  for  life. 


CHAP.  III. 

DESCRIPTION  OP  THE  INDIVIDUAL  BONES  OF  THE  SKULL. 

Os  FRONTIS.  This  bone  is  compared  with  a clam- 
shell. It  is  of  a semicircular  shape,  hollowed  like  a shell. 
It  is  marked  on  the  inside  by  a spine,  or  prominent  line, 
which  divides  the  hollow  of  the  bone  into  two  equal  parts, 
and  gives  rise  to  a membranous  partition,  which  divides  and 
supports  the  hemispheres  of  the  brain.  It  is  marked  on  its 
external  surface  by  those  high  ridges  on  which  the  eye-brows 
are  placed,  and  by  two  prominences,  which  are  hollow  ca- 
verns, named  the  sinus  (or  cavites)  of  the  frontal  bone.  Its 
orbitary  plates  are  the  two  thin  and  delicate  lamellae  that  de- 
part from  the  general  direction  of  the  bone,  and  stand  out 
horizontally,  so  as  to  form  a part  of  the  socket  for  the  eye,  or, 
as  it  were,  a roof  defending  the  upper  part  of  the  eye,  and  a 
floor  for  supporting  the  lower  part  of  the  brain ; and  these 
two  orbitary  plates  leave  an  open  space,  in  which  is  incased 
the  chief  part  of  the  aethmoid  bone,  viz.  incissura  sethmoidea. 

The  frontal  bone  stands  connected  with  the  parietal  bones 
by  tbe  coronal  suture ; it  is  connected  to  the  great  ala  of  the 
sphenoid  bone  by  the  sutura  spheno  frontalis ; while  its  or- 
bitary plates  are  united  to  the  lesser  ala  by  the  linea  spheno 
frontalis.  The  nasal  bones  are  attached  to  it  by  part  of  the 
transverse  suture  of  the  face.  The  cribriform  plate  of  the 
aethmoid  bone  is  united  to  the  orbitary  plates  by  the  linea 
sethmoidea  frontalis,  and  looking  into  the  orbits  the  same  or- 


36 


description  of  the 


bitaiy  plates  are  seen  to  be  contiguous  to  the  ossa  plana  and 
ossa  unguis ; and,  lastly,  the  ossa  inalarum  are  attached  to 
the  frontal  bone  by  the  extremities  of  the  transverse  suture  of 
the  face. 

The  first  point  to  be  remarked,  is  the  superciliary  ridge, 
on  which  the  eye-brows  are  placed  : it  is  a prominent  arched 
line,  corresponding  in  size  and  length  with  tiie  eye-brow  which 
it  supports : over  this  line  the  integuments  are  loose : here 
many  arteries  perforate  the  bone,  which  are  properly  the  nu- 
tritious arteries  of  this  part  of  the  bone  ; and  we  find  all  over 
the  superciliary  ridge  many  small  holes  through  which  these 
arteries  had  passed.  Among  these,  there  is  one  hole  which  is 
larger,  and  which  is  distinguished  from  the  rest ; for  its  use  is 
not  like  the  others,  to  transmit  arteries  to  the  bone,  but  to  give 
passage  to  the  frontal  nerve  and  a small  artery  which  comes 
out  from  the  orbit,  to  mount  over  tbe  forehead.  Sometimes 
the  nerve  turns  freely  over  the  border  of  the  orbit,  and  makes 
no  mark,  or  but  a slight. one  : often  lying  closer  upon  tbe  bone, 
it  forms  a notch  ; but  most  commonly,  in  place  of  turning  fair- 
ly over  the  edge  of  the  orbit,  it  passes  obliquely  through  the 
superciliary  ridge,  and  by  perforating  the  bone,  makes  a hole  : 
this  hole  is  named  the  superciliary  hole.  The  artery 
wliir  h comes  from  the  eye  to  go  out  upon  the  forehead  is 
named,  where  it  passes,  the  superciliary  artery;  and  higher  up 
upon  the  lorehead,  the  frontal  artery  : it  establishes  a commu- 
nication betwixt  tlie  internal  arteries  of  the  eye,  and  external 
arteries  of  the  forehead  and  temple.  We  are  always  warned 
of  the  danger  of  wounding  arteries  where  they  pass  through 
bones ; and  strange  stories  are  told  of  the  terrible  bleedings 
which  have  risen  from  this  artery,  wounded  near  its  hole,  and 
of  the  convulsions,  palsies,  and  loss  of  sight,  which  have  arisen 
from  the  accidents,  wounds  or  lacerations  of  this  frontal  nerve  ; 
stories  deliv^ered  on  such  authorities  as  we  dare  not  refuse,  and 
yet  cannot  easily  believe. 

The  second  foramen  is  the  foramen  orbitale  internum, 
which  transmits  a branch  of  the  ophthalmic  division  of  the  fifth 
nerve  into  the  cranium,  and  finally  into  the  nose.  There  is 
frequently  another  foramen  in  the  orbital  plate,  which  trans- 
mits a small  vessel  from  the  orbit  to  the  nose. 

The  orbitary,  or  superciliary  ridge,  ends  by  two  processes, 
which,  forming  the  angles  of  tbe  eye,  are  named  the  angular 
PROCESSES.  The  frontal  bone  has,  therefore,  four  angular 
processes:  1.  The  two  internal  angular  processes,  forming 

the  internal  angles  of  the  eyes ; and  2.  The  two  external  an- 
gular processes  which  form  the  external  angles  of  each  eye. 

Betwixt  the  two  internal  angular  processes  there  is  the  na- 


INDIVIDUAL  BONES  OF  THE  SKULL.  37 

SAL  POINT  or  puocEss.  This  nasal  process  is  a small  sharp 
projecting  point,  occupying  that  space  which  is  exactly  in  the 
midfile  of  the  bone,  and  is  betwixt  the  two  internal  angular 
pr  »cesses.  It  is  very  irregular  and  rough  all  round  its  root, 
for  supporting  the  two  small  nasal  bones ; and  this  gives  them 
a firm  seat,  and  such  a hold  upon  the  root  of  the  forehead, 
that  they  oftener  are  broken  than  displaced. 

From  the  external  angular  process  there  extends  backwards 
and  upwards  the  temporal  ridge  or  spine. 

At  the  inner  end  of  the  superciliary  ridge,  is  that  bump 
which  marks  the  place  of  the  frontal  sinus,  which  also  indi- 
cates their  size  ; for  where  this  rising  is  not  found,  the  sinuses 
are  wanting,  or  are  very  small ; but  this  is  no  sure  nor  absolute 
mark  of  the  presence  of  these  sinuses,  which  often,  in  the  flat- 
test foreheads,  are  not  entirely  wanting. 

The  sinuses*  of  the  os  frontis  are  two  in  number,  one  on 
either  side  above  the  root  of  the  nose  : they  are  formed  by  a 
receding  of  the  two  tables  of  the  skull  from  each  other:  they' 
are  formed  at  first  with  the  common  cancelli,  and  at  first  they 
resemble  the  common  cancelli,  as  if  they  were  only  laiger 
cells : gradually  they  enlarge  into  two  distinct  cavities,  often 
of  very  considerable  size,  going  backwards  into  the  orbitary 
plate,  or  sideways  into  the  orbitary'  ridge,  or  upwards  through 
one  half  of  the  frontal  bone;  and.Ruysch  had,  in  a giantess 
(puella  gigantica,)  seen  them  pass  the  coronal  suture,  and  ex- 
tend some  way  into  the  parietal  bones. 

The  two  sinuses  of  either  side  are  divided  by'  a partition ; 
but  still  they'  communicate  by  a small  hole : sometimes  the  par- 
tition is  almost  wanting,  and  there  are  only'  crossings  of  the 
common  lamellated  substance ; and  though  the  communica- 
tion with  one  another  is  not  always  found,  they  never  fail  to 
communicate  with  the  nose  : this  indeed  seems  to  be  their 
chief  use  ; for  the  frontal  sinuses  are  the  beginning  of  a great 
train  of  cells,  which,  commencing  thus  in  the  frontal  bone,  ex- 
tend through  the  tethmoidal,  sphenoidal,  and  maxillary  bones, 
so  as  to  form  an  organ  of  great  extent  and  use  belonging  to 
the  nose  ; but  perhaps  not  so  much  for  extending  the  organ  of 
smelling,  as  for  making  a more  sonorous  voice  ; for  we  have 
no  proof  that  the  sinuses  are  part  of  the  organ  of  smell ; un- 
less we  should  accept  of  this  as  a proof,  that,  by  smelling  of 
strong  volatiles,  pain  shoots  upwards  into  the  forehead ; though 

* The  word  ninus  is  used  in  two  senses ; we  call  the  cavities  or  cells,  within  the  substance 
of  a bone,  the  sinuses  of  that  hone ; as  the  sinuses  of  the  forehead,  of  the  sphenoid,  sthinoid 
or  m ixilhry  bones  we  call  also  certain  great  veins  by  the  same  name  of  sinuses  ; thus  the 
great  veins  being  enlarged  where  they  a[tproach  the  heart,  and  the  veins  being  particularly 
large  in  the  bi’ain  and  the  womb,  we  call  them  the  sinuses  of  the  heart,  of  the  bi-ain,  and  of 
the  womb. 


38 


DESCRIPTION  OF  THE 


by  the  same  rule,  the  eyes  should  be  also  a part  of  the  same 
organ,  since  they  are  pained,  and  tears  begin  to  flow  : but  we 
do  Cpiow  that  they  belong  to  the  voice,  and  raise  its  tone,  for 
we  feel  the  trembling  note  resound  through  all  these  cells,  so 
that  the  voice  is  sonorous  while  they  are  free  ; is  damped 
when  the  sinuses  are  oppressed  by  their  membranes  being 
thickened  by  cold  ; or  is  almost  suppressed  when  the  sinuses 
are  entirely  closed  ; or  when,  by  venereal  ulcers,  the  curtain 
of  the  palate  is  consumed,  no  part  of  the  voice  passing 
upwards  into  the  nose,  it  is  almost  lost. 

This  has  given  rise  to  a very  common  mistake  : that  as 
these  sinuses  are  wanting  in  the  child  whose  forehead  is  flat, 
as  they  enlarge  gradually,  and  are  fully  formed  about  the  fif- 
teenth year,  the  vox  rauca,  the  breaking  of  the  voice,  which 
is  observed  about  that  time,  must  be  owing  to  the  evolution  of 
these  cells : but  the  female  voice  does  not  undergo  the  same 
change  by  the  evolution  of  these  cells  ; and  castration,  which 
surely  can  have  no  effect  on  these  cavities,  keeps  down  the 
eunuch’s  to  the  treble  key  of  the  female  voice.*  The  mis- 
take lies  ill  supposing  these  cavities  to  raise  the  tone  or  note 
in  which  we  speak,  while  they  only  add  clearness  and  strength. 
The  membrane  which  lines  these  cavities  is  thin,  exquisitely 
sensible,  and  is  a continuation  of  the  common  membrane  of 
the  throat  and  nose.  A thin  humour  is  poured  out  upon  its 
surface  to  moisten  it  and  keep  it  right.  This  the  ancients  did 
not  consider  as  a mere  lubricating  fluid,  but  as  a purgation  of 
the  brain,  drawn  from  the  pituitary  gland,  which  could  not  be 
diminished  without  danger,  and  which  it  was  often  of  conse- 
quence to  promote. 

They  are  subject  to  one  accident  chiefly,  viz.  insects  which 
nestle  there,  and  produce  inconceivable  distress;  and  it  is  par- 
ticular, that  they  more  frequently  lodge  in  the  frontal  sinuses, 
than  in  the  cavities  of  any  of  the  other  bones.  In  sheep  and 
dogs  such  insects  are  very  frequent,  as  in  seeking  their  food, 
they  carry  their  nose  upon  the  ground  ; and  it  has  been  prov- 
ed, or  almost  proved,  that  in  man  they  arise  from  a like  cause. 
Indeed,  what  can  we  suppose,  but  that  they  get  there  by 
chance  ; thus,  a man  having  slept  in  barns,  was  afflicted  with 
dreadful  disorders  in  the  forehead,  which  were  relieved  upon 
discharging  from  the  nose,  a worm  of  that  kind  which  is  pecu- 
liar to  spoiling  corn  ; while  others  have  had  the  complaint, 
by  sleeping  upon  the  grass.  But  there  is  something  very  par- 
ticular in  this,  that  far  the  greater  number  of  these  worms  have 

* I have  seen  a boy  of  four  years  of  age,  whose  parts  of  generation  were  prematurely 
developed  with  busby  hair  upon  tlie  pubes.  This  man-ebild  had  the  rough  broken  voice, 
though  the  bones  of  the  forehead  were  flat.  C.  B. 


INDIVIDUAL  BONES  OF  THE  SKULL. 


39 


been  of  the  centipede  kind  ; generally  long,  an  inch  in  length, 
with  one  hundred,  or,  according  to  Linnseus,  one  hundred  and 
twelve  feet,  and  not  unfrequently  covered  with  hair.  There 
are  reports  which  seem  to  prove,  that  some  have  died  of  this 
complaint,  and  in  a very  miserable  way.  In  many  cases  it  has 
been  attended  with  delirium  ; and  in  almost  every  instance  it 
has  continued  for  years.  No  wonder,  then,  that  the  trepan- 
ning of  these  sinuses  has  often  been  proposed ; but  I have 
never  read  of  a well  marked  case,  so  that  we  could  be  assur- 
ed beforehand  of  finding  worms : they  have,  in  most  cases, 
been  discovered  rather  by  chance.  The  patient  might  be  re- 
lieved on  easier  terms,  by  the  injection  of  aloes,  assafoetida, 
myrrh,  the  use  of  snuff  or  smoaking,  and  pressing  the  fumes 
upwards  into  the  nose.  Much  should  be  tried,  before  under- 
taking a dangerous  operation  on  such  slender  proofs. 

It  maybe  right  in  cases  of  fractures,  to  decline  applying  the 
trepan  above  the  sinuses,  unless  a fracture  cannot  be  raised  in 
any  easier  way ; and  we  must  be  especially  careful  to  distin- 
guish a fracture  of  the  outer  table  only,  from  entire  fractures 
of  this  bone.  For  Palfin  says,  that  the  outer  table  being  bro- 
ken, and  the  natural  mucus  of  the  sinus  being  corrupted  and 
flowing  out,  has  been  mistaken  for  the  substance  of  the  brain 
itself.  And  Paree,  who  first  gives  this  caution,  affirms,  “ that 
“ he  had  seen  surgeons  guilty  of  this  mistake,  applying  the 
“ trepan,  and  so  killing  their  unhappy  patients.”* 

The  SPINE  or  ridge  which  runs  upon  the  internal  surface  of 
the  frontal  bone,  is  to  be  observed,  as  it  gives  a firm  bold  to 
the  falx,  or  that  perpendicular  membrane,  which  running  in  the 
middle  of  the  head,  divides  and  supports  the  brain.  This  is 
more  or  less  prominent  in  different  skulls,  and  according  to  the 
age.  The  spine  is  more  prominent  at  its  root ; but  as  it  ad- 
vances up  the  forehead,  it  decreases,  and  often  ends  in  a 
groove.  The  spine  gives  firm  hold  for  the  falx,  and  the  groove 
lodges  the  great  longitudinal  sinus,  or  in  other  words,  the  great 
vein  of  the  brain,  which  runs  along  the  head,  in  the  course  of 
the  perpendicular  partition,  or  falx.  At  the  root  of  this  spine, 
there  is  a small  blind  hole  ; it  is  named  blind,  because  it  does 
not  pass  quite  through  the  bone,  and  the  beginning  of  the  falx, 
dipping  down  into  this  hole,  gets  a firmer  bold.  The  ancients, 
thinking  that  the  hole  descended  through  both  tables  into  the 
nose,  believed  that  the  dangerous  and  ungovernable  bleedings 
at  the  nose  must  be  througii  this  hole,  and  from  the  fore  end, 
or  beginning  of  the  longitudinal  sinus. 

* For  a more  perfect  account  of  the  pathology  of  the  sinuses,  see  the  Sui'gery,  4t». 
vel.  ii. 


40 


DESCRIPTION  OP  THE 


The  ORBITARY  PROCESS  already  described,  is  the  most  re- 
markable point  of  the  frontal  bone.  Tlie  orbitary  process- 
es are  two  thin  plates,  departing  from  the  general  direction  of 
the  bone,  and  standing  inwards  at  right  angles : they  cover  the 
eye,  and  support  the  brain.  By  the  continual  rolling  of  the 
eye,  and  the  pressure  of  the  brain,  they  are  extremely  thin 
and  transparent  ; the  rolling  of  the  eye  makes  them  exqui- 
sitely smooth  below,  and  on  their  upper  surfaces,  they  are  im- 
pressed with  the  frequent  convolutions  of  the  brain  ; so  that  a 
■wound  through  the  eye  endangers  more  than  the  eye  ; for  it 
passes  easily  forward  into  the  brain,  and  is  instantly  fatal ; it  is 
the  aim  of  the  fencer,  and  we  have  known  in  this  country 
a young  man  killed  by  the  push  of  a foil,  which  had  lost  its 
guard. 

Upon  the  orbitary  plate,  and  just  under  the  superciliary 
ridge,  there  are  two  depressions  in  the  socket pf  each  eye; 
the  one  is  very  small,  and  deeper  at  the  inner  corner  of  the 
eye,  under  the  superciliary  hole,  which  is  the  mark  of  the 
small  cartilaginous  pulley,  in  which  the  tendon  of  one  of  the 
muscles  of  the  eye  plays  ; the  other,  a more  gentle  and  diffu- 
sed hollow,  lies  under  the  external  angular  process,  is  not 
deep,  but  is  wide  enough  to  receive  the  point  of  a finger,  and 
is  the  place  w'here.the  lachrymal  gland  lies,  that  gland  which 
secretes  the  tears,  and  keeps  the  eye  moist.* 

PARIETAL  BONE. — The  parietal  bones  form  much  the 
greater  share  of  the  cranium  : they  are  more  exposed  than 
any  others,  are  the  most  frequently  broken,  and  the  most  easily 
trepanned ; for  the  parietal  bones  are  more  uniform  in  their 
thickness,  and  more  regular  in  their  two  tables  and  diploe,  than 
any  others.  But  the  accidental  varieties  of  pits  and  depression 
are  very  frequent  in  them,  and  the  sinus  or  great  vein,  and  the 
artery  which  belongs  to  the  membranes  of  the  brain,  both 
make  their  chief  impressions  upon  this  bone. 

The  square  form  of  the  bone  produces  four  angles  ; and  in 
surgery,  we  speak  of  the  frontal,  the  occipital,  the  mastoidean, 
and  temporal  angles,  of  the  parietal  bone.|  It  has  deeply  ser- 
rated edges,  which  unite  the  two  bones  with  each  other,  and 
with  the  occipital  and  frontal  bones.  All  the  corners  of  this 
bone  are  obtuse,  except  that  one  which  lies  in  the  temple,  and 
which,  running  out  to  a greater  length  than  the  other  corners, 
is  sometimes  named  the  spinous  or  temporal  process  of  the 
parietal  bone,  though  there  can  be  no  true  process  in  a bone  so 

* )n  addition,  as  points  of  demonstration,  we  may  add  the  emineniix  frantales,  and  su- 
purdliares. 

+ It  enters  into  the  wonal,  tlie  sagittal,  the  lamhdmdal,  and  the  sijmrwm  sutures. 


INDIVIDUAL  BONES  OF  THE  SKULL. 


41 


sjegular  and  flat.  The  lower  edge  of  the  bone  is  a neat  semi- 
circle, which  joins  the  parietal  to  the  temporal  bone  ; and  the 
edge  of  each  is  so  slaunted  off,  that  the  edge  of  the  temporal 
overlaps  the  edge  of  the  parietal,  with  a thin  scale,  forming  the 
squamous  suture.  About- an  inch  above  the  squamous  suture, 
there  is  a semi- circular  ridge,  where  the  bone  is  particularly 
white  and  hard  ; and  rays  extend  downwards  from  this,  con- 
verging towards  the  jugum.  The  white  semi-circular  line 
represents  the  origin  of  the  temporal  muscle ; and  the  con- 
verging lines  express  the  manner  in  which  the  fibres  of  the 
muscle  are  gathered  into  a smaller  compass,  to  pass  under  the 
jugum,  or  arch  of  the  temple.  The  sagittal  suture,  or  meet- 
ing of  the  two  parietals,  is  marked  with  a groove  as  big  as  the 
finger,  which  holds  the  longitudinal  sinus,  or  great  vein  of  the 
brain  ; but  the  groove  is  not  so  distinctly  seen,  unless  the  two 
bones  are  put  together  ; for  one  half  of  this  flat  groove  belongs 
to  each  bone. 

The  great  artery  of  the  dura  mater  touches  the  bone  at  that 
angle  of  it  which  lies  in  the  temple.  It  traverses  the  bone 
from  corner  to  corner,  spreading  from  the  first  point,  like  the 
branches  of  a tree  : it  beats  deep  into  the  bone  w'here  it  first 
touches  it ; but  where  it  expands  into  branches,  its  impressions 
are  very  slight ; commonly  it  makes  a groove  only,  but  some- 
times it  is  entirely  buried  in  the  bone ; so  that  at  the  lower 
corner  of  the  parietal,  we  cannot  escape  cutting  this  vessel,  if 
we  are  forced  to  operate  with  the  trepan. 

There  is  but  one  hole  in  the  parietal  bone  : it  is  small  and 
round,  is  within  one  inch  of  the  meeting  of  the  lambdoidal  and 
sagittal  sutures,  and  gives  passage  to  a small  external  vein, 
which  goes  inwards  to  the  sinus,  and  to  a small  artery  which 
goes  also  inwards  to  the  dura  mater,  or  rather  to  the  falx. 

On  the  inner  surface  of  the  bone,  and  near  the  sagittal  edge, 
we  very  often  see  a pit  or  foveae,  which  receives  one  of  those 
bodies  which  are  called  glands,  of  the  dura  mater. 

The  lateral  sinus  makes  a depression  on  the  inside  of  the 
mastoid ean  angle. 

The  meeting  of  the  frontal  and  parietal  bones,  being  imper- 
fect in  the  child,  leaves  that  membranous  interstice  which,  by 
some,  is  named  folium  or  folliolum,  from  its  resembling  a 
trefoil  leaf,  and  was  named  by  the  ancients  hypothetically, 
bregma,  fons,'*  or  fountain  ; they  thinking  it  a drain  of  moisture 
from  the  brain ; and  so  the  parietal  bones  are  named  ossa 
bre£;matis. 

O 

*■  The  word  piilsatilis,  or  fons  pulsatile,  or  beating  fountain,  was  added,  because  we  feel 
the  beating  of  the  arteries  of  the  brain  there. 

VOL.  I.  F 


42 


DESCRIPTION  OF  THE 


OS  OCCIPITIS,  has  also  the  names  of  os  memorice,  and 
os  nervosum.*  It  is  the  thickest  of  the  cranial  bones,  but  it  is 
the  least  regular  in  its  thickness,  being  transparent  in  some 
places,  and  in  others  swelling  into  ridges  of  very  firm  bone. 
It  gives  origin  or  insertion  to  many  of  the  great  muscles,  which 
move  the  head  and  neck ; it  supports  the  back  part  of  the 
brain,  contains  the  cerebellum  or  lesser  brain,  transmits  the 
spinal  marrow,  and  is  marked  with  the  conflux  of  the  chief 
sinuses,  or  great  veins  of  the  brain. 

This  bone  is  united  to  the  parietal  bones  by  tlie  lambdoid 
suture,  to  the  mastoidean  portions  of  the  temporal  bone  by 
the  additamentum  suturae  lainbdoidalis,  laterally  and  forward 
it  is  attached  to  the  petrous  portion  of  the  temporal  bone,  and 
at  its  lower  and  most  anterior  part,  it  is  attached  to  the  sphe- 
noid bone,  by  that  peculiar  bond  of  union  called  synostosis. 

The  EXTERNAL  SURFACE  is  exceedingly'  irregular,  by  the 
impressions  of  the  great  muscles  of  the  neck  : betwixt  the 
insertions  of  the  muscles,  projecting  lines  are  on  the  bone. 
In  the  middle  of  the  bone,  and  betwixt  the  muscles  of  oppo- 
site sides,  there  runs  a ridge  from  above  downward  ; at  the 
upper  margin  of  the  insertion  of  the  trapezius,  there  is  formed 
a superior  transverse  spine  or  ridge,  and  in  the  same  way,  di- 
rectly above  the  insertion  of  the  recti,  which  make  two  irre- 
gular depressions,  there  is  an  inferior  transverse  spine.  In  a 
strong  man,  advanced  in  years,  where  the  ridges  and  hollows 
are  strongly  marked,  the  point  where  the  superior  transverse 
crosses  the  perpendicular  one,  it  is  so  very  promine  t,  as  to  be 
named  the  posterior  tuberosity  of  the  occipital  bone. 

The  INTERNAL  SURFACE.  Opposite  to  these  ridges  there 
are  similar  crucial  ridges  within  ; but  larger,  more  regular, 
smooth,  and  equal,  and  making  only  one  transverse  line,  and 
one  perpendicular  line.  The  tentorivm  cere.bdln  super-exte.n- 
sum,  is  a diaphragm  or  transverse  partition,  wiiich  crosses  the 
skull  at  its  back  part ; cuts  off  from  the  rest  of  the  cranium 
the  hollow  of  the  occipital  bone,  appiopriates  that  cavity  for 
tlie  cerebellum,  and  defends  the  cerebellum  from  the  weight 
and  pressure  of  the  brain.  This  tentorium,  or  transverse 
membrane,  is  attached  to  the  gre.ivt  internal  ridge  of  the 
occipital  bone.  In  the  angle  where  this  membrane  is  fixed  to 
the  ridge,  lies  the  great  sinus  or  vein,  which  is  called  longitu- 
dinal sinus,  while  it  is  running  along  the  head  ; but  the  same 

* In  Hejinning  the  demonstration,  we  point  out  its  divisions  : I.  Pars  orcipitalis.  2.  Pars 
lateralis  or  condyloidea.  'i  Pars  hasilaris  or  cunifnrinis ; wliich  at  birth  are  distinct  hones 
di\  id.-d  by  cartilage  It  is  also  necessary  to  name  its  angles,  viz.  the  superior  or  parietal 
angle,  and  the  mastoidean  angle. 


INDIVIDUAL  BONES  OF  THE  SKULL. 


43 


sinus,  dividing  in  the  back  of  the  head,  into  two  great  branches, 
changes  its  name  with  its  direction ; and  the  forkings  of  the 
vessel  are  named  the  right  and  left  lateral  sinuses,  which  go 
down  through  the  basis  of  the  skull ; and  being  continued 
down  the  neck,  are  there  named  the  great  or  internal  jugular 
veins.  This  forking  of  the  longitudinal,  into  the  lateral  sinuses, 
makes  a triangulak  or  tripoo-ltke  groove,  which  follows 
the  internal  ridges  of  the  occipital  bone  : and  above  and  be- 
low the  transverse  ridge  there  are  formed  four  plain  and 
smooth  hollows.  The  two  upper  ones,  are  above  the  tento- 
rium, and  contain  the  posterior  lobes  of  the  brain  ; the  two 
lower  ones  are  under  the  tentorium,  and  hold  the  lobes  of  the 
cerebellum  or  little  brain. 

Processes.  The  processes  or  projections  of  the  occipital 
bone  are  few  and  simple.  1.  There  is  a part  of  the  bone 
which  runs  forward  from  the  place  of  the  foramen  magnum, 
lies  in  the  very  centre  of  the  base  of  the  skull,  joins  the  occi- 
pital to  the  sphenoidal  bone,  and  which,  both  on  account  of 
its  place,  (wedged  in  the  basis  of  the  skull,)  and  of  its  shape, 
which  is  rather  small,  and  somewhat  of  the  form  of  a wedge, 
is  named  the  cuniform,  or  wedge-like  process  of  the  occi- 
pital bone.  On  the  inside  of  this  part  of  the  bone  is  a slight 
hollow,  to  which  the  name  of  fossa  basilaris  is  given,  and  lateral 
to  this  the  groove  of  the  lower  petrous  sinus  may  be  observ- 
ed. And  there  are  two  small  oval  processes,  or  button  like 
projections,  which  stand  olF  from  the  side,  or  rather  from  the 
forepart  of  the  foramen  magnum,  or  great  hole,  and  which, 
being  lodged  in  joints  belonging  to  the  upper  bone  of  the 
neck,  form  the  hinge  on  which  the  head  moves.  These  two 
processes  are  named  the  condyles  of  the  occipital  bone. 
They  are  not  very  prominent,  but  rather  flattened  ; are  of  an 
oval  form,  and  have  their  fore-ends  turned  a little  towards 
each  other  ; so  that  by  this  joint  the  head  moves  directly 
backwards  or  forwards,  but  cannot  turn  or  roll.  The  turning 
motions  are  performed  chiefly  by  the  first  bones  of  the  neck. 
Round  the  root  of  each  condyle,  there  is  a roughness,  which 
shows  where  the  ligament  ties  this  small  joint  to  the  corres- 
ponding bone  of  the  neck. 

On  the  low’er  part  of  the  cuniform  process,  there  are  tw'o 
tubercles  for  the  attachment  of  the  recticapitis  anteriores. 
Near  the  condyle,  and  immediately  behind  the  foramen  lacer- 
um  there  is  a tubercle  for  the  rectus  capitis  lateralis. 

Holes. — These  condyles  stand  just  on  the  edge  of  the  fora- 
men magnum,  or  great  hole  of  the  head,  which  transmits  the 
spinal  marrow,  or  continuation  of  the  brain  ; and  the  edges  of 
this  hole  (which  is  almost  a regular  circle)  are  turned  and 


44i 


DESCRIPTION  OF  THE 


stnootlied  ; a little  thicker  at  the  lip,  and  having  a roughness 
behind  that  giving  a firna  hold  to  a ligament,  which,  departing 
from  this  hole,  goes  down  through  the  whole  cavity  of  the 
spine,  forming  at  once  a sheath  for  the  spinal  marrow,  and  a 
ligament  for  each  individual  bone.  There  passes  down 
through  this  great  hole  the  spinal  marrow,  and  the  vertebral 
vein.  There  comes  up  through  it  the  vertebral  arteries, 
which  are  of  great  importance  and  size  ; and  a small  nerve, 
which,  from  its  coming  backwards  from  the  spine  to  assist 
certain  nerves  of  the  brain,  is  named  the  spinal  accessory 
nerve. 

The  second  hole  is  placed  a little  behind  the  ring  of  the 
foramen  magnum,  and,  just  at  the  root  of  either  condyle,  is 
round  and  large,  easily  found,  and  sometimes  it  is  double  ; it 
transmits  the  ninth  pair,  or  great  lingual  nerve. 

There  is  another  hole  smaller,  and  less  regular  than  this  last. 
It  is  exactly  behind  the  condyle,  while  the  lingual  hole  is  be- 
fore it.  It  is  for  permitting  a small  vein  of  the  neck  to  enter 
and  drop  its  blood  into  the  great  lateral  sinus  ; but  often  it  is 
not  formed,  and  this  trifling  vein  gets  in  by  the  great  occipital 
hole. 

We  shall  describe  with  the  temporal  bone  that  wide  hole 
which  is  common  to  the  temporal  and  occipital  bones,  and 
which  transmits  the  great  lateral  sinus. 

TEMPORAL  BONE. — The  temporal  bone  is,  in  the  child, 
two  bones  ; which  retain  their  original  names  of  pars  petrosa 
and  pars  squamosa.  The  whole  bone  is  very  irregular  in  its 
thickness,  and  hollows,  and  processes.  The  pars  sq,uamosa  is 
a thin  or  scaly  part,  rises  like  a shell  over  the  lower  part  of  the 
parietal  bone,  and  is  smoothed  and  flattened  by  the  rubbing  of 
the  temporal  muscle.  The  pars  petrosa,  often  named  os 
L.APIDOSUM,  or  stony  bony,  is  hard,  irregular,  rocky;  just  in- 
wards towards  the  basis  of  the  skull ; , contains  the  organs  of 
hearing,  and,  of  course,  receives  and  transmits  all  the  nerves 
which  are  connected  with  the  ear.*  There  is  a third  portion 
of  this  bone,  viz.  the  mastoidean  angle,  which  is  thick  and 
hard,  is  divided  into  cells,  and  forms  those  caverns  which  are 
supposed  to  be  chiefly  useful  in  reverberating  the  sound. 

The  squamous  part  is  grooved,  to  make  the  squamous  suture ; 
is  scolloped  or  fringed ; and  exceedingly  thin  on  its  edge  ; it 
is  radiated,  in  consequence  of  its  original  ossification  shooting 
out  its  rays.  The  petrous  part  again  is  triangular,  unequal  by 
the  cavities  of  the  ear;  it  has  a very  hard,  shining,  polished- 
like  surface ; exceeded  in  hardness  by  nothing  but  the  enamel 


* Theiaterior  and  posterior  semi-circular  canals  are  protuberant  upon  its  surfaces. 


1^'D1VIDUAL  BONES  OF  THE  SKULL. 


43 


the  teeth.  Where  it  projects  into  the  base,  it  has  several 
open  points,  which  are  filled  up  with  cartilaginous  or  ligamen- 
tous substance  ; and  its  occipital  angle  is  connected  with  the 
other  bones  by  the  additamentum  suturs  squamosae. 

The  temporal  bone  closes  the  cranium,  upon  the  lower  and 
lateral  part ; backwards  it  is  connected  by  the  additamentum  su- 
turaelambdoidalis  to  the  occipitalbone ; by  the  squamous  suture 
and  the  additamentum  sutura:  squamosa,  it  isjoined  to  the  parie- 
tal bone  ; whilst  anteriorly  it  is  united  to  the  sphenoid  bone  by 
the  spheno-temporal  suture,  the  spinous  process  of  the  sphe- 
noid bone  being  deeply  wedged  betwixt  the  petrous  and  squa- 
mous portions  of  the  temporal  bone. 

Processes.  The  zygomatic  process  rises  broad  and  flat 
before  the  ear ; grows  gradually  smaller  as  it  stretches  for- 
ward to  reach  the  cheek-bone  : it  forms  w'ith  it  a zygoma, 
yoke,  or  arch  of  the  temple,  under  which  the  temporal  muscle 
plays.  The  temporal  muscle  is  strengthened  by  a firm  cover- 
ing of  tendon,  which  stretches  from  the  upper  edge  of  this 
zygoma  to  the  white  line  on  the  parietal  bone  ; and  several 
muscles  of  the  face  arise  from  the  low'er  edge  of  the  zygoma, 
particularly  one  named  inasseter,  which  moves  the  jaw;  and  one 
named  zygomaticus,  or  distorter  oris,  because  it  draws  the  an- 
gle of  the  mouth.  The  zygomatic  process  is  united  by  a short 
suture  to  the  cheek  bone. 

The  STYLOID  process  is  so  named  from  a slight  resem- 
blance to  the  stylus,  or  point  with  which  the  ancients  engraved 
their  writings  on  tables  of  w'ax.  It  is  cartilaginous  long  after 
birth ; even  in  the  adult,  it  is  not  completely  formed  ; it  is  ex- 
ceedingly delicate  and  small ; and  when  its  cartilaginous  point 
is  fairly  ossified,  as  in  old  men,  it  is  sometimes  two  inches 
long.  It  stands  obliquely  out  from  the  basis  of  the  head,  and 
is  behind  the  jaws ; so  that  it  gives  convenient  origin  to  a 
ligament  which  goes  downwards  to  support  the  os  hyoides,  or 
bone  of  the  tongue  ; and  it  is  the  origin  of  many  curious  mus- 
cles, chiefly  of  the  throat  and  jaws.  One  slender  muscle  going 
downwards  from  the  styloid  process,  and  expanding  over  the 
pharynx,  is  called  stylopharyngeus ; one  going  to  the  os 
hyoides,  is  the  stylohyoideus  ; one  going  to  the  tongue,  is  the 
stylo-glossus : and  since  the  process  is  above  and  behind  these 
parts,  the  muscles  must  all  pull  backw'ards  and  upwards,  rais- 
ing according  to  their  insertions,  one  the  pharynx,  another  the 
os  hyoides,  another  the  tongue. 

Processus  vaginalis  will  not  be  easily • found,  nor  ac- 
knowledged as  a process ; for  it  is  only  a small  rising  of  a 
ridge  of  the  bone,  with  a rough  and  broken-like  edge,  on  the 
middle  of  which  the  styloid  process  stands  : it  is,  in  short,  the 


46 


DESCRIPTION  OF  THE 


root  of  the  styloid  process  which  anatomists  have  chosen  to 
observe,  though  it  gives  origin  to  no  particular  part ; and  which 
they  iiave  named  vaginalis,  as  if  it  resembled  a sheath  for  the 
styloid  process. 

Mastoidcus  or  mammillaris,  is  a conical  nipple-like  bump, 
like  the  point  of  tlie  thumb  ; it  projects  from  under  the  ear, 
and  is  easily  felt  with  the  finger  without ; it  is  hollow,  with 
many  cells  which  enlarge  the  tympanum,  or  middle  cavity  of 
the  ear,  and  are  thought  to  reverberate  and  strengthen  the 
sound.  Under  its  root,  there  is  a deep  and  rough  rut  which 
gives  a firm  hold  to  the  first  belly  of  the  digastric  muscle  ; and 
the  point  or  nipple  of  this  process  is  the  point  into  which  the 
mastoid  muscle  is  inserted  from  before ; and  the  complexus 
obliquus  and  trachelomastoideus  muscles  from  behind.  It  has 
been  proposed  of  late  years,  that,  in  certain  cases  of  deafness, 
we  should  open  this  part  with  the  trepan. 

The  AUDITORY  HRocKss  is  just  the  outer  margin  of  the  hole 
of  the  ear.  It  is  in  a child  a distinct  ring,  which  is  laid  upon 
the  rest  of  the  bone.*  The  membrane  of  the  ear  is  extended 
upon  this  ring,  like  the  head  of  a tambour  upon  its  hoop, 
whence  this  is  named  the  circle  of  the  tambour  by  the  French, 
and  bv  us  the  drum  of  the  ear.  In  the  adult,  this  ring  is  fair- 
ly united  to  the  bone,  and  is  named  the  processus  auditorius; 
and  may  be  defined  a circle,  or  ring  of  bone,  with  a rough  ir- 
regular edge;  the  drum  or  membrane  of  the  ear  is  extended 
upon  it,  and  the  cartilaginous  tube  of  the  ear  is  fixed  to  it;  and 
this  ring  occupies  the  space  trom  the  root  of  the  mamillary  to 
the  root  of  the  zygomatic  process. 

Betwixt  this  and  the  mastoid  process  there  is  a kind  of  fis- 
sure, the  rima  mastoidea. 

The  lower  jaw  is  articulated  with  this  bone  bj  a shallow 
fossa,  which  is  anterior  to  the  auditory  process,  and  at  the 
root  oi  the  zygomatic  process.  A tubercle  immediately  be- 
fore this  articulating  surface  deepens  it.  A fissure  may  be 
observed  in  nearly  the  middle  of  the  cavity,  which  is  for  the 
attachment  of  the  ligament,  which  unites  the  intermediate 
cartilage  of  tliis  articulation  This  fissure  divides  the  proper 
articular  or  glenoid  cavity  from  that  fossa  which  gives  lodge- 
ment to  a deep  portion  of  the  j>arotid  gland 

Holcs.  The  temporal  bone  is  perforated  with  many  holes, 
each  of  which  relates  to  the  organ  of  hearing ; some  for  per- 
mitting nerves  to  enter;  others  to  let  them  out;  others  for 
the  free  passage  of  air  to  the  internal  ear. 

The  MKATUs  AiJDiToRius  F.xTEKNUs  (the  circlc  of  which 
has  been  dercribed)  is  covered  with  the  membrane  of  the 
* In  brutes  it  is  indeed  a process  standing  out. 


'INDIVIDUAL  BONES  OF  THE  SKULL. 


47 


drum,  and  communicates  the  vibratory  motion  of  the  air  for 
moving  and  exciting  the  internal  organs. 

The  MEATUS  AuniTOKius  JNTERNUS  is  that  hole  by  which 
the  auditory  nerves  have  access  to  the  ear.  It  is  a very  large 
hole,  seated  upon  the  back  of  the  pars  petrosa,  which  is  of  a 
triangular  form.  The  hole  is  at  first  large,  smooth,  almost  a 
regular  circle,  with  a sort  of  round  lip.  Within  this  are  seen 
many  small  holes,  the  meaning  of  which  is  this:  the  auditory- 
nerve  is  double  from  its  very  origin  in  the  brain  : it  consists, 
in  fact,  of  two  distinct  nerves,  the  portio  dura,  and  the  portio 
mollis.  The  portio  mollis  is  a large,  soft  and  delicate  nerve, 
which  constitutes  the  true  organ  of  hearing;  and  when  it  is 
admitted  into  the  ear,  it  is  expanded  into  a thin  web  which 
spreads  over  all  the  cavities  of  the  ear,  as  the  cochlea,  semi- 
circular canals,  &c.  The  portio  dura,  the  smaller  part  of  the 
nerve,  passes  indeed  through  the  ear,  but  it  is  quite  a foreign 
nerve;  it  is  not  distributed  within  the  ear;  it  keeps  the  form 
of  a distinct  cord,  and,  passing  through  the  temporal  bone,  it 
conies  out  upon  the  cheek,  where  it  is  expanded  ; so  that  the 
portio  dura  is  a nerve  of  the  face,  passing  through  the  ear,  but 
forming  no  part  of  that  organ.  Thus  the  two  nerves,  the 
portio  dura  and  mollis,  enter  together;  they  fill  the  greater 
hole,  and  then  they  part : the  portio  dura,  entering  by  one 
distinct  hole,  takes  its  course  along  a distinct  canal,  the  aque- 
duct of  Fallopius  from  which  it  comes  out  upon  the  cheek; 
while  the  portio  mollis,  entering  by  many  smaller  holes  into 
the  cochlea,  semi-circular  canals,  and  other  internal  parts  of 
the  ear,  is  expanded  in  these  cavities  to  form  the  proper  organ 
of  hearing. 

There  is  a small  hole  which  will  admit  the  point  of  a pin 
upon  the  fore  part  of  the  petrous  bone.  This  hole  receives  a 
small  twig  reflected  from  the  fifth  pair  of  nerves : the  nerve  is 
as  small  as  a sewing  thread  ; it  can  be  traced  along  the  petrous 
bone  by  a small  groove,  which  conducts  it  to  the  hole ; and 
when  it  enters  the  ear,  it  goes  into  the  same  canal  with  the 
portio  dura,  and  joins  itself  to  it. 

The  hole  by  which  the  portio  dura  passes  out  upon  the 
cheek,  is  found  just  before  the  mastoid,  and  behind  the  stv- 
loid  process ; and  being  betwixt  the  two,  it  is  named  the  sxv- 
Lo-MASToiD  hole,  and  is  so  small,  as  just  to  admit  a pin. 

The  hole  for  the  Eustachian  tube  is  very  irregular.  No  air 
can  pass  through  the  membrane  of  the  drum  ; and  as  air  is  ne- 
cessary within  the  ear,  it  is  conveyed  upwards  from  the  palate 
by  the  itek  a palato  ad  aurem,  or,  as  it  is  commonly  called, 
the  Eustachian  tube.  This  tube  is  long,  and  of  a trumpet 
form  ; its  mouth,  by  which  it  opens  behind  the  nostril,  is  wide 


48 


DESCRIPTION  OF  THE 


enough  to  receive  the  point  of  the  finger,  it  grows  gradually 
smaller  as  it  advances  towards  the  ear:  it  is  cartilaginous  in 
almost  its  whole  length  ; very  little  of  it  consists  of  firm  bone  ; 
so  that  the  student,  in  examining  the  skull,  will  hardly  find  the 
Eustachian  tube  for  the  cartilage  being  rotten  away,  nothing 
is  left  but  that  end  of  the  canal  that  is  next  the  ear,  and 
which  opens  both  above  and  below,  ragged,  irregular,  and 
broken. 

When  we  have  a sore  throat,  the  pain  extends  up  along  this 
tube  into  the  ear;  when  we  have  a cold,  both  our  voice  and 
our  hearing  is  hurt ; the  one  by  the  stuffing  of  the  sinuses,  the 
other  by  the  stuffing  of  the  Eustachian  tube.  When  we  shut 
the  nose  and  mouth,  and  blow  strongly,  we  feel  a crackling  in 
the  ear,  as  in  the  place  of  the  Eustachian  tube  ; when  we  dive, 
we  feel  the  same,  by  the  condensation  of  the  air ; and  sometimes 
by  forcing  the  air  strongly  upwards  through  the  ear,  or  by  vo- 
mits, obstruction  of  the  Eustachian  tube,  and  the  deafness 
which  attends  that  accident,  are  very  suddenly,  and,  we  may 
say,  violently  removed ; or  sometimes  the  cure  is  attempted 
by  syringing,  or  by  cleaning  the  mouth  of  this  tube  with  a 
probe,  just  as  we  do  the  external  ear. 

Above  and  to  the  outside  of  the  Eustachian  tube  there  is  a 
narrow  canal  which  conveys  the  nerve  called  corda  tympani. 
This  nerve,  traversing  the  tympanum,  enters  into  the  aqueduct 
of  Falopius,  and  unites  with  the  facial  nerve. 

On  the  inside  of  the  Eustachian  tube  we  may  observe  a ca- 
nal which,  leading  backwards,  opens  into  the  cavity  of  the  tym- 
panum with  a mouth  like  a spoon,  it  gives  lodgement  to  the 
long  muscle  of  the  maleus. 

The  other  holes  do  not  relate  to  the  ear,  and  are  chiefly  for 
transmitting  the  great  blood  vessels  of  the  brain. 

The  CAROTID  ARTERV,  the  chief  artery  of  the  brain,  enters 
into  the  skull  near  the  point  of  the  petrous  bone,  and  just 
before  the  root  of  the  styloid  process.  The  artery  goes  first 
directly  upwards,  then  obliquely  forwards  through  the  bone, 
and-  then  again  upwards,  to  emerge  upon  the  inside  of  the 
skull;  so  that  the  carotid  makes  the  form  of  an  Italic  S,  wdien 
it  is  passing  through  the  substance  of  the  bone ; and,  in  place 
of  a mere  hole,  we  find  a sort  of  short  canal,  wide,  a little 
crooked,  and  very  smooth  within.  There  seems  to  be  a par- 
ticular design  in  this  angle,  which  the  artery  is  forced  to  make  : 
perhaps  it  is  designed  to  abate  the  violence  with  which  the 
blood  would  drive  forwards  into  the  brain  ; for  in  many  of  the 
lower  animals,  there  are  still  more  particular  provisions  than 
this,  the  arteiy  being  prevented  from  entering  the  brain  in 
one  great  trunk,  by  a curious  division  into  many  branches,. 


INDIVIDUAL  BONES  OF  THE  SKULL. 


49 


which  meet  again.  It  is  at  this  particular  point  that  we  are 
sensible  in  our  own  body  of  the  beating  of  these  two  great  ar- 
teries ; and  Haller  is  at  pains  to  inform  us,  that,  during  a fever, 
he  felt  this  beating  in  a very  distressing  degree. 

The  CHEAT  LATERAL  SINUS  comcs  out  in  part  through  the 
temporal  bone,  to  form  the  interna!  jugular  vein.  The  course 
of  the  sinus  may  be  easily  traced  by  the  groove  of  the  occi- 
pital bone  downwards,  behind  the  pars  petrosa  : there  also  it 
makes  a deep  groove,  and  ends  with  a large  intestine-like 
turn,  which  makes  a large  cavity  in  the  temporal  bone,  big 
enough  to  receive  the  point  of  the  finger.  The  sinus  passes 
out,  not  by  any  particular  hole  in  the  temporal  bone,  but  by 
what  is  called  a common  hole,  viz.  formed  one  half  by  the 
temporal  and  one  half  by  the  occipital  bone.  This  hole  is 
very  large ; is  lacerated  or  ragged-like.  It  is  sometimes  di- 
vided into  two  openings,  by  a small  point,  or  spine  of  bone. 
The  larger  opening  on  one  side  of  that  point  transmits  the 
great  sinus,  where  it  begins  to  form  the  jugular  vein ; and  the 
smaller  opening  transmits  the  eighth  nerve  of  the  skull,  or 
par  vagum,  which  goes  down  towards  the  stomach,  along  with 
the  jugular  vein. 

There  is  a small  furrow  upon  the  very  angle  or  ridge  of  the 
petrous  bone,  which  is  made  by  a small  vein  of  the  brain,  the 
superior  petrous  sinus  going  towards  the  end  of  the  lateral  si- 
nus. 

There  is  a small  hole  on  the  outside  of  this  bone,  in  the 
occipital  angle ; or  rather  the  hole  is  oftener  found  in  the  line 
of  the  suture  (the  additamentum  sutura'  squamosa).  Some- 
times it  is  in  the  occipital  bone  ; or  sometimes  it  is  wanting  : 
it  transmits  a trifling  vein  from  without,  into  the  great  sinus, 
or  a small  artery  going  to  the  dura  mater. 

There  are  two  very  small  canals,  which  probably  carry  lym- 
pbatics  from  the  inner  cavities  of  the  ear;  they  have  been 
called  aqueductus  vestibuli,  and  aqueductus  cochlea;  they 
open  on  the  petrous  bone,  near  the  internal  auditory  foramen. 

Among  the  irregular  depressions  on  the  different  faces  of 
this  bone  are  sometimes  enumerated  these:  the  groove  al- 
ready mentioned  on  the  mastoid  process  for  the  lodgement  of 
the  head  of  the  digastricus  ; certain  cerebral  fossas,  which  are 
the  impressions  of  the  convolutions  of  the  brain  upon  the  in- 
side of  the  squamous  portion;  the  jugular  fossa,'  or  thimble- 
like depression,  made  by  the  first  turn  of  the  great  jugular 
vein  ; the  temporal  sinuosity  for  the  lodgement  of  the  tempo- 
ral muscle ; and,  lastly,  we  observe  in  a well  marked  bone, 
the  sulci  for  the  artery  of  the  dura  mater. 

G 


50 


DESCRIPTION  OF  THE 


The  ETHMOID  BONE — Is  perhaps  one  of  the  most 
curious  bones  of  the  human  body.  It  appears  almost  a cube, 
not  of  solid  bone,  but  exceedingly  light,  spongy,  and  consist- 
ing of  many  convoluted  plates,  which  form  a net-work  like 
honey-comb.  It  is  curiously  enclosed  in  the  os  frontis, 
betwixt  the  orbitary  processes  of  that  bone.  One  horizontal 
plate  receives  the  olfactory  nerves,  which  perforate  that  plate 
with  such  a number  of  small  holes,  that  it  resembles  a sieve, 
whence  the  bone  is  named  cribriform,  or  sethmoid  bone. 
Other  plates,  dropping  perpendicularly  from  this  one,  re- 
ceive the  divided  nerves,  and  give  them  an  opportunity  of 
expanding  into  the  organ  of  smelling ; and  these  bones,  upon 
which  the  olfactory  nerves  are  spread  out,  are  so  much  con- 
voluted, as  to  extend  the  surface  of  this  sense  very  greatly, 
and  are  named  spongy  bones.  Another  flat  plate  lies  in  the 
orbit  of  the  eye,  which  being  very  smooth,  by  the  rolling  of 
the  eye,  is  named  the  os  planum,  or  smooth  bone ; so  that 
the  aethmoid  bone  supports  the  forepart  of  the  brain,  receives 
the  olfactory  nerves,  forms  the  organ  of  smelling,  and  makes 
a chief  part  of  the  orbit  of  the  eye ; and  the  spongy  bones, 
and  the  os  planum,  are  neither  of  them  distinct  bones,  but 
parts  of  this  sethmoid  bone.  Thus  the  aethmoid  is  united  to 
the  frontal  bone,  by  the  linea  aethmoidea  frontalis,  and  to 
the  sphenoid  bone  by  a similar  line  of  contact,  visible  on  the 
inside  of  the  base  of  the  cranium.  Looking  into  the  orbit,  we 
again  see  a union  with  the  frontal,  and  with  the  sphenoidal 
and  palate  bones.  Its  perpendicular  plate  stands  connected 
to  the  back  part  of  the  nasal  process  of  the  frontal  bone  ; the 
vomer  is  attached  to  the  back  part  of  this  plate.  The  ossa 
unguis  close  the  cells  of  this  bone  anteriorly. 

The  CRIBRIFORM  PLATE  is  exceedingly  delicate  and  thin, 
lies  horizontally  over  the  root  of  the  nose,  and  fills  up  neatly 
the  space  betwixt  the  two  orbitary  plates  of  the  frontal  bone. 
The  olfactory  nerves,  like  two  small  flat  lobes,  lie  out  upon 
this  plate,  and,  adhering  to  it,  shoot  down  like  many  roots 
through  this  bone,  so  as  to  perforate  it  with  numerous  small 
holes,  as  if  it  had  been  dotted  with  the  point  of  a pin,  or  like 
a nutmeg  grater. 

This  plate  is  horizontal ; but  its  processes  are  perpendicular, 
one  above,  and  three  below. 

The  first  perpendicular  process  is  what  is  called  crista 
OALLi,  a small  perpendicular  projection  somewhat  like  a cock’s 
comb,  but  exceedingly  small,  standing  directly  upwards  from 
the  middle  of  the  cribriform  plate,  and  dividing  that  plate 
into  two  ; so  that  one  olfactory  nerve  lies  upon  each  side  of 
the  crista  galli ; and  the  root  of  the  falx,  or  septum,  betwixt, 
the  two  hemispheres  of  the  brain,  begins  from  this  process. 


INDIVIDUAL  BONES  OF  THE  SKULL. 


51 


The  foramen  caecum,  or  blind  hole  of  the  frontal  bone,  is 
formed  partly  by  the  root  of  the  crista  galli,  which  is  very 
smooth,  and  sometimes,  it  is  said,  hollow  or  cellular. 

Exactly  oposite  to  this,  and  in  the  same  direction  with  it, 
{i.  e.)  perpendicular  to  the  aethmoid  plate,  stands  out  the 
NASAL  PLATE  of  the  aethmold  bone.  It  is  sometimes  called 
the  azygous,  or  single  process  of  the  aethmoid,  and  forms  the 
beginning  of  that  septum  or  partition  which  divides  the  two 
nostrils.  This  process  is  thin,  but  firm,  and  composed  of  solid 
bone  ; it  is  comonly  inclined  a little  to  one  or  other  side,  so  as  to 
make  the  nostrils  of  unequal  size.  The  azygous  process  is  uni- 
ted with  the  vomer,  which  forms  the  chief  part  of  the  parti- 
tion ; so  that  the  septum,  or  partition  of  the  nose,  consists  of 
this  azygous  process  of  the  aethmoid  bone  above,  of  the  vomer 
below,  and  of  the  cartilage  in  the  fore  or  projecting  part  of  the 
nose;  but  the  cartilage  rots  away,  so  that  w'hatever  is  seen  of 
this  septum  in  the  skull,  must  be  either  of  the  aethmoid  bone 
or  the  vomer. 

The  lateral  parts  of  the  aethmoid  bone  consists  of  a series  of 
cells  communicating  with  each  other,  and  which  are  called 
the  labyrinths.  The  cells  of  the  labyrinth  are  closed  by  the 
external  plate  called  os  planum.  These  cells  belong  to  the 
organ  of  smelling,  and  are  useful  by  detaining  the  effluvia  of 
odorous  bodies,  and  by  reverberating  the  voice. 

From  each  of  these  labyrinths  there  hangs  down  a spongy 
BONE,  one  hanging  in  each  nostril.  They  are  each  rolled  up 
like  a scroll  of  parchment ; they  are  very  spongy ; are  covered 
with  a delicate  and  sensible  membrane,  and  when  the  olfac- 
tory nerves  depart  from  the  cribriform  plate  of  the  Jethmoid 
bone,  they  attach  themselves  to  the  septum,  and  to  these  upper 
spongy  bones,  and  expand  upon  them  so,  that  the  convolutions 
of  these  bones  are  of  material  use  in  expanding  the  organ  of 
smelling,  and  detaining  the  odorous  effluvise  till  the  impres- 
sion be  perfect.  Their  convolutions  are  more  numerous  in  the 
lower  animals,  in  proportion  as  they  need  a more  acute  sense. 
They  are  named  spongy,  or  turbinated  bones,  from  their  con- 
volutions, resembling  the  many  folds  of  a turban. 

The  ORBITARY  PLATE  of  the  aethmoid  bone  is  a large  sur- 
face, consisting  of  a very  firm  plate  of  bone,  of  a regular 
square  form,  exceedingly  smooth  and  polished  : it  forms  a 
great  part  of  the  socket  for  the  eye,  lying  on  its  inner  side. 
When  we  see  it  in  the  detached  bone,  we  know  it  to  be  just 
the  flat  side  of  the  aethmoid  bone  ; but  while  it  is  incased  in 
the  socket  of  the  eye,  we  should  believe  it  to  be  a small  square 
bone  ; and  from  this,  and  from  its  smoothness,  it  has  got  the 
distinct  name  of  os  planum. 


52 


BESCRIPTION  OF  THE 


The  os  UNGUIS  sliould  also,  perhaps,  be  counted  as  a part 
of  this  bone ; lor  though  the  os  unguis,  when  observed  in  the 
orbit,  seems  to  be  a small  detached  hone,  thin,  like  a scale, 
and  of  the  size  of  the  finger  nail  (whence  it  has  its  name,)  yet 
in  the  adult  the  os  unguis  is  firmly  attached  to  the  r tlmioid 
bone,  comes  along  with  it  when  we  separate  the  pieces  of  the 
sknll,  and  when  the  os  unguis  is  pared  olf  from  the  sethmoid 
bone,  it  exposes  the  cells. 

This  os  unguis,  then,  is  a small  scaly-like  plate,  in  the  inner 
corner  of  the  orbit  just  over  the  nose.  We  find  in  it'  that 
groove  which  holds  the  lachrymal  sac,  and  conducts  it  to  the 
nose  ; and  it  is  this  thin  bone  that  we  perforate  in  making  the 
new  passage  into  the  nose,  when  there  is  an  obstruction  in  the 
natural  duct. 

The  cells  of  the  sethmoid  bone,  which  form  so  important  a 
share  of  the  oigan  of  smell,  are  arranged  in  great  numbers, 
along  the  spongy  bone.  They  are  small  neat  cells,  much  like 
a honey-comb,  and  regularly  arranged  in  two  rows,  pai’ted 
from  each  other  by  a thin  partition  ; so  that  the  os  planum 
seems  to  have  one  set  of  cells  attached  to  it,  while  another 
regular  set  of  cells  belong  in  like  manner  to  the  spongy  bones. 
The  cells  are  thus  twelve  in  number,*  opening  into  each  other, 
and  into  the  nose. 

These  cells  are  frequently  the  seat  of  venereal  ulcers,  and 
the  spongy  bones  are  the  surface  where  polypi  often  sprout 
up.  And  from  the  general  connections  and  forms  of  the  bone, 
w'e  can  easily  understand  how  the  venereal  ulcer,  when  deep  in 
the  nose,  having  got  to  these  cells,  cannot  be  cured,  but  un- 
dermines all  the  face ; how  the  venereal  disease,  having  af- 
fected the  nose,  soon  spreads  to  the  eye,  and  how  even  the 
brain  itself  is  not  safe-  We  see  the  danger  of  a blow  upon 
the  nose,  which,  by  a force  upon  the  septum,  or  middle  par- 
tition, might  depress  the  delicate  cribriform  plate,  so  as  to 
oppress  the  brain  with  all  the  elfects  of  a fiactured  skull,  and 
without  any  operation  which  could  give  relief.  And  we  also 
see  much  danger  in  pulling  aw'ay  polypi,  which  are  firmly  at- 
tached to  the  upper  spongy  bone. 

SPHENOIDAL  BONE. — The  sphenoidal  bone  completes 
the  cranium,  and  closes  it  below.  It  is  named  sphenoid  cu- 
NiFOHM,  or  WEUGE-LiKE  bone,  from  its  being  incased  in  the 
very  basis  of  the  skull;  or  it  is  named  os  multifohme,  from 
its  irregular  shape.  It  is  united  to  fourteen  distinct  bones.  It 
is  much  of  the  shape  of  a bat,  whence  it  is  often  named  the 

* Tlie  number  is  commonly  twelve,  but  not  regularly  so. 


IJ^DIVIDUAL  BONES  OF  THE  SKULL. 


53 


PTERYGOID  BONE,  its  temporal  processes  being  like  extended 
wings  ; its  proper  pterygoid  processes  like  feet ; its  middle 
like  the  body  and  bead  of  a bat ; its  wing-like  processes,  are 
in  the  hollow  of  the  temple,  forming  a part  of  the  squamous 
suture,  and  also  composing  a part  of  the  orbit  of  the  eye. 
Its  pterygoid  processes  hang  over  the  roof  of  the  mouth, 
forming  the  back  of  the  nostrils  : the  body  is  in  tbe  very  cen- 
tre of  the  skull,  and  transmits  five  of  the  nerves  from  the  brain, 
besides  a reflected  nerve  ; but  still  the  body  bears  so  small  a 
proportion  to  the  bone,  that  we  have  not  a regular  centre  to 
which  all  tbe  processes  can  be  referred ; so  that  we  are  al- 
ways, in  describing  this  bone,  moving  forwards  from  point  to 
point,  from  one  process  or  hole  to  the  next. 

PROCESSES. — The  ala:,  or  avings,  often  named  tempo- 
ral processes,  rise  up  in  the  temple,  to  form  part  of  the  hollow 
of  the  temple  ; and  the  wings  of  the  sphenoid  bone  meeting 
tbe  frontal,  parietal,  and  temporal  bones,  by  a thin  scaly  edge, 
they  make  part  of  the  squamous  suture,  and  give  a smooth 
surfece  for  the  temporal  muscle  to  play  upon. 

The  other  side  of  this  same  process  looks  towards  the  socket 
of  the  eye,  and  has  a very  regular  and  smooth  surface  ; it  is 
opposite  to  the  os  planum.  As  the  tethmoid  bone  forms  part 
of  the  inside  of  the  orbit,  the  wing  of  the  sphenoid  bone  forms 
part  of  the  outside  of  the  orbit;  and  so  the  surface  turned 
towards  the  eye  is  named  the  okbitaky  process  of  the  sphe- 
noid bone,  or  okbitary  plate  of  the  great  ala. 

The  surface  of  the  great  wing  which  looks  backwards,  re- 
ceives the  middle  lobe  of  the  cerebrum  and  is  called  tbe 
CEREBRAL  FOSSA  ; and  that  which  is  external  and  receiving 
the  temporal  muscle,  is  called  the  temporal  fossa. 

The  lower,  or  back  part  of  this  bone  runs  out  into  a nar- 
row point,  which  sinks  in  under  the  petrous  portion  of  tbe 
temporal  bone,  and  being  sharp  pointed,  it  is  named  the  spi- 
nous PROCESS.  It  is  very  remarkable  for  a small  hole  which 
permits  the  great  artery  of  the  dura  mater  to  enter. 

The  point  of  this  spinous  process  projects  in  the  form  of  a 
very  small  peak,  which  will  hardly  be  found  by  the  student. 
It  projects  from  the  basis  of  the  skull  just  within  the  condyle 
of  the  lower  jaw,  and  being  a small  point,  like  the  point  of  the 
stylus,  or  iron-pen,  it  also  is  named  styloid  process. 

Tiie  lesser  wing  of  Ingkasias  next  attracts  the  eye.  It 
is  that  part  of  the  bone  which  unites  (by  harmonia)  with  the 
orbitary  plate  of  the  frontal  bone,  and  with  theiethraoid  bone. 

This  lesser  wing  projects  laterally  into  the  transverse  spi- 
nous PROCESS. 


54 


DESCRIPTION  OF  THE 


The  PTERYGOID  PROCESSES*  are  four  in  number,  two  on 
either  side.  They  are  those  processes,  upon  which  (with  the 
spinous  process)  the  bone  naturally  stands,  and  which,  when  we 
compare  it  with  a bat,  represent  the  legs ; one  of  each  side, 
is  named  external  pterygoid,  the  other  is  named  the  internal 
pterygoid  process. 

Each  EXTERNAL  PTERYGOID  PROCESS  is  thin  and  broad,  and 
extends  farther  backwards.  Each  internal  pterygoid  pro- 
cess is  taller  and  more  slender,  and  not  so  broad.  It  has  its  end 
rising  higher  than  the  other,  and  tipped  with  a small  neat  hook, 
named  the  hook  of  the  pterygoid  process,  (viz.  the  hamular 
PROCESS.)  The  inner  pterygoid  processes,  form  the  back  of 
the  nostrils.  The  hook  of  the  pterygoid  process,  is  called 
the  hook  of  the  palate,  of  which  it  forms  the  backmost  point. 
The  musculus  circumdexus  vel  tensor  palati,  rising  from  the 
mouth  of  the  Eustachian  tube,  turns  with  a small  tendon  round 
this  hook,  like  a rope  over  its  pulley;  and  the  great  muscles 
of  the  lower  jaw,  the  only  ones  for  moving  it  sideways,  or  for 
its  grinding  motions,  arise  from  the  pterygoid  processes.  Be- 
twixt the  two  processes  there  is  a hollow  which  is  called  the 
fossa  pterygoidea. 

The  AZYGOUS  PROCESS,!  so  named,  from  its  being  single, 
because  it  is  seated  in  the  centre  of  the  bone,  so  that  it  can 
have  no  fellow.  It  stands  perpendicularly  downwards,  and 
forwards,  over  the  centre  of  the  nose,  and  its  chief  use  is  to 
give  a firm  seat  or  insertion  for  the  vomer  or  bone  which 
forms  the  septum.  The  vomer,  or  proper  bone  of  the  par- 
tition, stands  with  a split  edge,  astride  over  this  process,  so  as 
to  have  a very  firm  seat.  A kind  of  union  which  has  been 
called  gomphosis. 

The  CLYNOJD  PROCESSES  have,  like  many  parts  of  the  human 
body,  a very  whimsical  name,  very  ill  suited  to  express  their 
form ; for  it  is  not  easy,  in  this  instance,  to  acknowledge  the 
likeness  of  four  little  knobs  to  bed-posts ; yet  the  clynoid  pro- 
cesses are  very  remarkable.  The  two  anterior  clynoid 
PROCESSES  are  small  bumps,  rather  sharp,  projecting  back- 
wards, and  terminating  in  two  flat  projecting  points.  The 
POSTERIOR  CLYNOID  PROCESSES  rise  about  an  inch  farther 
backwards,  and  are,  as  it  were,  opposed  to  the  others.  They 
rise  in  one  broad  and  flat  process,  which  divides  above  into 

* There  ii  some  confusion  in  ■ this  name,  since  pterygoid  signifles  aliform,  or  wing-like 
processes. 

f Azygous  is  a term,  which  is  applied  to  such  parts  as  have  no  fellow ; because  almost  al- 
.^vays  the  parts  on  one  side  of  the  body  are  balanced  by  similar  and  corresponding  parts  on  the 
other  side.  When  tliey  stand  in  tl)e  centre  of  the  body,  or  are  otherwise  single,  we  call 
them  azygous,  and  so  the  azygous  process  of  the  sethmoid  and  sphenoid,  and  other  bones ; or 
the  azygous  vein,  which  runs  in  the  centre  of  the  thorax,  and  is  single. 


INDIVIDUAL  BONES  OF  THE  SKULL.  55 

two  points,  small  and  round,  or  nobby  at  their  points ; and  they 
look  forwards  towards  the  anterior  clynoid  processes. 

The  TUBERCULUM  OLIVARE  is  an  eminence  betwixt  the  an- 
terior clynoid  process  and  before  the  sella  turcica. 

The  SELLA  TURCICA  EPHiPPUM,  Or  Turkish  saddle,  is  the 
space  enclosed  by  these  four  processes,  and  is  well  named. 
The  sella  turcica,  supports  the  pituitary  gland,  an  appendage 
of  the  brain,  the  use  of  which  is  unknown.  The  carotid  ar- 
teries rise  up  by  the  sides  of  the  sella  turcica,  and  mark  its 
sides  with  a broad  groove.  The  optic  nerves  lie  upon  a 
groove  at  the  fore  part  of  the  sella  turcica,  betw'ixt  the  two 
anterior  clynoid  processes ; and  sometimes  the  two  anterior 
processes  stretch  backwards,  till  they  meet  the  posterior  ones, 
and  form  an  arch,  under  which  the  carotid  artery  passes. 
Often  the  posterior  clynoid  knobs  cannot  be  fairly  distinguish- 
ed ; since,  in  many  skulls,  they  form  but  one  broad  process. 

On  the  side  of  the  posterior  clynoid  process,  the  carotid  ar- 
tery as  it  rises  impresses  its  form  upon  the  bone. 

The  cone  or  triangular  process  is  singularly  placed  in  obscu- 
rity, when  the  bones  are  in  union,  and  in  separating  the  sphe- 
noid bone  it  is  very  apt  to  be  broken  olF.  This  process  closes 
the  cell,  and  projects  laterally  towards  the  deepesLpart  of  the 
orbit,  but  so  as  to  be  concealed  by  the  palate  bone. 

This  bone  has  also  its  cells,  for  all  that  part  w'hich  we  call 
the  body  of  the  bone,  all  the  sella  turcica,  that  space  which  is 
betwixt  the  clynoid  processes  within  and  the  azygous  process 
without,  is  hollowed  into  one  large  cell,  divided  with  a middle 
partition.  It  is,  indeed,  less  regular  than  the  other  cells ; it  is 
sometimes  very  large,  sometimes  it  is  not  to  be  found  ; it  has 
other  trifling  varieties  which  it  were  idle  to  describe.  As  it 
communicates  with  the  sethmoid  cells,  it  probably  performs 
one  office  with  them,  is  almost  a continuation  of  them,  so  that 
when  any  one  is  less  or  wanting,  the  others  are  proportionally 
larger. 

HOLES. — The  sphenoid  bone  is  so  placed  in  the  very 
centre  of  the  skull,  that  its  holes  transmit  the  principal  nerves 
of  the  skull,  and  it  bears  the  marks  of  the  chief  arteries. 

The  OPTIC  HOLES  are  large  round  holes,  just  under  each 
anterior  clynoid  process.  We  trace  the  optic  nerves  by  a 
large  groove  into  each  optic  hole ; and  an  artery  goes  along 
with  them,  named  the  opthalmic  artery,  nearly  the  size  of  a 
crow-quill,  twisting  round  the  optic  nerve,  and  giving  arteries 
to  the  eye-lids,  muscles,  and  lachrymal  gland,  but  most  espe- 
cially to  the  ball  and  humours  of  the  eye  itself.  This  ocular 
or  ophthalmic  artery  comes  off  from  the  great  carotid,  while 
it  lies  by  the  side  of  the  sella  turcica ; and  it  is  a branch  again 


56 


DESCRIPTION  OP  THE 


of  this  ocular  artery,  which  goes  out  upon  the  forehead, 
through  the  superciliary  notch,  or  hole. 

The  FOHAiWKN  LACEKUM  is  next  in  order,  and  is  so  named, 
because  it  is  a wide  slit.  It  is  also  called  superior  orbitary 
fissure.  The  foramen  lacerum  is  wide  near  the  sella  turcica, 
grows  gradually  narrower,  as  it  goes  out  towards  the  temple, 
till  it  terminates  almost  in  a slit.  The  upper  line  of  the  fora- 
men lacerum  is  formed  by  the  transverse  spinous  process,  ex- 
tending outwards,  sharp  and  flat. 

The  nerves  of  the  skull  are  counted  from  before  backwards. 
There  are  nine  nerves,  proper  to  the  skull ; the  1st,  or  olfac- 
tory nerve,  perforates  the  cribriform  bone ; the  2d,  or  optic 
nerve,  passes  through  the  optic  hole ; the  3d,  4th,  part  of 
the  5th  and  6th  pairs  of  the  nerves,  pass  through  this  foramen 
lacerum,  or  wide  hole,  to  go  also  into  the  orbit.  The  optic 
nerve  forms  the  proper  organ  of  vision.  The  smaller  nerves 
of  the  3d,  4th,  5lh,  and  6th  pairs,  go  to  animate  its  muscles, 
and  passing  through  the  orbit,  to  mount  upon  the  forehead,  or 
go  downwards  into  the  nose. 

The  FORAMEN  ROTUNDUM  is  named  from  its  round  shape. 
The  foramen  opticum  is  indeed  round,  but  it  has  already  got 
an  appropjiated  name.  Now  to  give  the  young  anatomist  a 
regular  notion  of  this,  and  of  the  next  hole,  we  must  enume- 
rate the  branches  of  the  5fh  pair.  The  fifth  nerve  of  the 
brain  is  as  broad  as  the  little  finger,  and  lies  by  the  side  of  the 
sella  turcica,  where  it  divides  into  three  lesser  nerves,  which 
are  called  branches  of  the  5th  pair.  The  first  branch  of  the 
5th  pair  is  destined  for  the  eye  ; the  second  branch  of  the  5th 
pair  for  the  upper  jaw;  the  third  branch  of  this  5th  pair  for 
the  lower  jaw : so  the  first  branch  of  the  5th  pair  passes 
through  the  foramen  lacerum  to  the  eye  ; the  second  branch 
of  the  5th  pair  passes  through  the  foramen  rotundum  to  the 
upper  jaw ; the  third  branch  of  this  great  nerve  passes  through 
the  foramen  ovale  to  the  lower  jaw;  and  if  we  had  any  faith 
in  the  docirines  of  nervous  sympathy,  we  should  say,  here  is 
a wide  sympathy  provided  among  the  nerves  of  the  eye,  the 
face,  and  the  lower  jaw. 

The  foramen  rotundum  then,  is  a hole  exactly  round,  pretty 
large,  opening  immediately  under  the  inner  end  of  the  fora- 
men lacerum,  and  transmitting  the  second  branch  of  the  5th 
pair  of  nerves  to  the  upper  jaw. 

The  FoitiMEiN  OVALF  is  an  oval  hole,  larger  than  the  foramen 
rotundum  ; about  half  an  inch  behind  it;  and  transmitting  the 
third  branch  of  the  5th  pair  to  the  lower  jaw. 

The  FORA.MEN  setNALE,  OF  SPINOUS  HOLE,  is  a Very  small 
round  hole,  as  if  made  with  a large  pin;  is  in  the  very  point 


INDIVIDUAL  BONES  OF  THE  SKULL. 


67 


of  the  spinous  process : is  one  third  of  an  inch  behind  the  oval 
hole,  and  transmits  the  small  artery,  less  than  a crow-quill, 
which  constitutes  the  chief  artery  of  the  dura  mater,  viz. 
that  artery  which  makes  its  impression  upon  the  parietal 
bone. 

There  is  still  another  hole,  which  transmits  a nerve,  curious 
in  this  respect,  that  it  is  not  going  out  from  the  skull  but  re- 
turning into  it ; for  the  second  branch  of  the  5th  pair,  or  the 
superior  maxillary  nerve,  sends  a small  branch  backwards, 
which  having  come  within  the  skull,  enters  the  temporal  bone, 
and  goes  to  join  itself  to  the  portio  dura  of  the  7th  pair,  and  in 
its  wav,  gives  a small  branch,  to  help  out  the  slender  begin- 
ning of  the  great  sympathetic  nerve.  This  retrograde  branch 
of  the  maxillary  nerve  gets  back  again  into  the  skull,  by  a hole 
which  is  found  just  under  the  root  of  each  pterygoid  process, 
whence  it  is  named  ptkiiygoid  HOLe  :*  or  by  many,  is  named 
after  its  discoverer,  the  Vidian  HoLc.f  This  hole  is  almost 
hidden  under  the  point  of  the  petrous  bone,  is  not  to  be  seen 
unless  in  the  separated  bones,  and  is  nearly  of  the  size  of  the 
spinous  hole. 

If  there  are  found  some  minute  holes  about  the  sella  tur- 
cica, they  are  the  marks  of  some  blood  vessels  entering  the 
bone  to  nourish  it. 

When  the  bones  of  the  cranium  are  united,  there  is  appa- 
rent an  irregular  hole,  which  corresponds  well  with  tjie  name 
foramen  lacerum  medius.  It  is  the  continuation  of  the  carotid 
foramen,  but  belongs  equally  to  the  sphenoid,  temporal,  and 
occipital  bones.  The  petrous  portion  of  the  temporal  bone 
points  to  it. 

There  is  a second  common  hole  formed  betwixt  the  sphe- 
noid, the  maxillary,  and  the  cheek-bone.  It  is  called  the 
spheno-maxillary  fissure. 

There  is  a third  common  hole  betwixt  the  cell  of  the  palate- 
bone  (in  the  separate  bone  a groove  may  be  noticed  on  the 
back  part  of  this  cell,)  and  the  root  of  the  pterygoid  process. 
This  hole  transmits  an  artery,  and  a twig  of  the  5th  pair  of 
nerves,  into  the  membrane  of  the  nose. 

* This  retrograde  twig  is  tire  little  nerve,  which  perforates  the  os  petrosum  on  its  fore- 
»art. 

' Vidus  Vidius,  a professor  of  Paris,  and  physician  to  Francis  the  First. 


H 


58 


OF  THE  BONES 


CHAP.  IV. 

OF  THE  BONES  OF  THE  FACE  AND  JAWS. 

The  face  is  composed  of  a great  number  of  small  bones^ 
which  are  grouped  together,  under  the  common  name  of  up- 
per-jaw. There  are  six  bones  on  either  side  of  the  face  j but 
as  their  names  could  convey  no,  distinct  notion  of  the  uses, 
forms,  or  places  of  these  bones,  to  enumerate  them  were  but 
waste  of  time  : they  have  indeed  sutures,  and  their  sutures 
have  been  very  regularly  enumerated  ; bui  these  bones  meet 
each  other  by  such  thin  edges,  that  no  indentation  nor  proper 
suture  is  formed.  None  of  these  sutures  run  for  any  length, 
or  are  of  any  note,  therefore  I have  only  this  to  say,  concern- 
ing the  sutures  of  the  face,  that  they  are  acknowledged  to  be 
purely  a consequence  of  the  ossification  having  begun  in  many 
points  : no  particular  design  of  nature  has  been  supposed. 
The  sutures,  if  they  require  names,  are  to  be  named  after  the 
bones  which  they  unite  together. 

OSSA  NASL — The  ossa  nasi  are  small  bones,  rather  thin, 
having  no  cancelli,  being  merely  firm  and  condensed  plates. 
They  are  convex  outwardly,  so  that  the  two  together  form 
nearly  an  arch.  They  are  opposed  to  each  other  by  a pretty 
broad  surface,  so  that  their  thin  arch  is  firm.  They  have  a flat 
rough  surface,  by  which  they  are  laid  upon  the  rough  surface 
of  the  frontal  bone  5 so  that  there  also  their  connection  is 
strong.  They  are  enclosed  by  a branch  of  the  upper  jaw- 
bone, which,  stretching  upwards,  is  named  its  nasal  process : 
and  they  lie  with  their  edges  under  it  in  one  part,  and  above  it 
in  anotlier,  in  such  a way  that  they  cannot  easily  be  forced  in. 
Lastly,  their  lower  edge  is  rough,  for  the  firm  attachment  of 
the  cartilages  of  the  nose  ; and  theirlowest  point,  or  that  where 
the  bones  of  the  nose  and  the  gristles  of  the  nose  are  joined, 
is  the  most  prominent  point  (or,  as  it  is  vulgarly  called,  the 
bridge)  of  the  nose  ; from  which  connection,  notwithstanding 
its  firmness,  the  cartilages  are  sometimes  luxated. 

The  only  point  like  a process  in  these  bones,  is  that  rough 
ridge  formed  by  their  union  which  projects  towards  the  cavity 
to  give  attachment  to  the  nasal  plate  of  the  aethmoid  bone. 

Os  UNGUIS,  so  named  from  its  being  of  the  size  and  shape  of 
the  nail ; or  sometimes  named  the  os  lachrymale,  from  its 
holding  the  duct  which  conveys  the  tears,  is  that  thin  scale  of 
bone  which  I have  described  as  belonging  to  the  os  sethmoides. 


OF  THE  FACE  AND  JAWS. 


59 


Ft  is  commonly  described  as  a distinct  bone  ; it  is  a thin  flat 
bone,  a single  scale,  without  any  cancelli,  having  only  one 
sharp  ridge  upon  it ; it  forms  a groove  for  lodging  the  lachry- 
mal sac,  and  is  of  course  found  in  the  inner  angle  of  the  eye 
at  its  forepart,  and  just  touching  the  top  of  the  nose.  One 
half  of  this  bone  is  behind  the  groove,  and  there  the  eye  rolls 
upon  it.  One  half  of  it  is  occupied  by  the  groove  for  the  nasal 
duct;  and  the  other  side  of  the  groove  is  formed  by  the  rising 
branch  or  nasal  process,  as  it  is  called,  of  the  upper  jaw-bone. 
The  os  unguis  is  delicate,  and  easily  broken,  being  as  thin  as 
a sheet  of  paper.  It  is  this  bone  which  is  pierced  in  the  ope- 
ration for  the  fistula  lachrymalis,  which  is  easily  done,  almost 
with  a blunt  steel  or  probe  ; and  the  chief  caution  is  to  perfo- 
rate in  the  place  of  the  groove,  as  that  will  lead  into  the  nose, 
and  not  behind  it,  which  would  carry  the  perforating  instru- 
ment into  the  sethmoidal  sinuses,  and  perhaps  wound  the 
spongy  bone  ; nor  more  forward,  as  that  would  be  ineffectual 
from  the  strength  of  the  nasal  process  of  the  maxillary  bone. 

This  bone  seems  peculiarly  liable  to  caries,  which  is  per- 
haps the  nature  of  all  these  thin  bones  ; for  as  they  have  no 
marrow,  they  must  depend  entirely  on  their  periosteum  for 
their  blood  vessels,  which  they  are  no  sooner  robbed  of  than 
they  die. 

Ossa  maxillaria  superiora. — The  upper  jaw-bones  are 
particularly  worthy  of  notice ; for  here  we  find  all  that  is  cu- 
rious in  the  face,  even  to  its  size  and  shape.  The  upper  jaw- 
bones are  of  a very  great  size,  forming,  as  it  were,  the  founda- 
tion or  basis  of  the  face.  They  send  a large  branch  upwards, 
which  forms  the  sides  of  the  nose  ; a broad  plate  goes  back- 
wards, which  forms  the  roof  of  the  palate.  There  is  a circu- 
lar projection  below  which  forms  the  alveoli,  or  sockets  of  the 
teeth.  The  upper  jaw-bones  are  quite  hollow  within,  forming 
a very  large  cavity,  which  is  capable  of  containing  an  ounce 
of  fluid,  or  more  ; and  the  size  of  this  cavity  seems  to  deter- 
mine the  height  of  the  cheek  bone  and  the  form  of  the  face  ; 
and  the  diseased  enlargement  of  this  cavity  raises  the  cheek- 
bone, lessens  the  eye,  and  deforms  the  face  in  a very  extraor- 
dinary degree. 

These  processes,  and  this  cavity  of  the  bone,  are  what  de- 
serve most  particular  notice. 

The  surfaces  or  plates  of  the  bone,  are  these  : External  or 
malar  surface  ; The  superior  or  orbital ; The  internal  oxiiasal; 
The  inferior  or  pa'atme. 

From  this  description  we  shall  understand  the  connections 
of  the  bone.  It  is  attached  forward  and  upward  to  the  nasal 
and  frontal  bones.  Laterally  to  the  cheek-bone,  and  in  the 


60 


OF  THE  BONES 


orbit  it  is  connected  with  the  lachrymal  and  aethmoid  bones  j 
towards  the  nasal  cavities,  it  has  the  vomer  palate- hone  and 
lower  spongy  bones  attached  to  it,  and  at  the  back  part  it 
touches  the  sphenoid  bone. 

Tile  first  process  is  the  nasal  process,  which  extends  up- 
wards to  form  the  sitie  of  the  nose.  It  is  arched  outwards,  to 
give  the  nostrils  shape.  Its  sides  support  the  nasal  bones  ; 
and  the  cartilages  of  the  al;e  nasi,  or  wings  of  the  nose,  are 
fixed  to  the  edges  of  this  process.  On  the  inside  and  root  of 
the  nasal  process  there  is  a rough  horizontal  ridge,  which  gives 
atlacliment  to  the  forepart  of  the  inferior  spongy  bone. 

A plate  of  this  bone  is  called  the  orbitary  process.  This 
thin  plate  is  the  roof  of  the  great  cavity,  which  occupies  this 
bone  entirely.  It  is  at  once  as  a roof  to  the  antrum  maxillare, 
and  as  a floor  for  the  eye  to  roll  upon.  There  is  a wide  groove 
along  the  upper  surface  of  this  plate,  in  which  the  chief 
branch  of  the  upper  maxillary  nerve  lies  : and  this  nerve,  na- 
med infra  orbitary  nerve,  from  its  lying  thus  under  the  eye, 
comes  out  by  a hole  of  the  jaw-bone  under  the  eye,  which  is 
named  infra  orbitary  hole.  And  thus  the  nerve  appearing  up- 
on the  cheek,  becomes  a nerve  of  the  face. 

This  great  bone  is  the  basis  upon  which  the  cheek-bone 
stands ; and  that  it  may  have  a firm  place,  there  is  a rough  and 
(as  anatomists  call  it)  scabrous  surface,  which  makes  a very 
firm  suture  with  the  cheek-bone  ; and  as  this  surface  rises  a 
little,  it  is  named  the  malar  process. 

From  the  lower  circle  of  the  upper  bone,  there  projects  a 
semi-circle  of  bone,  which  is  for  lodging  the  teeth  of  the  up- 
per jaw.  This  circle  of  bone  is  as  deep  as  the  fangs  of  the 
teeth  are  long.  And  it  may  be  very  truly  named  a process 
(processus  alveolar^s,)  since  it  does  not  exist  in  the  foetus, 
nor  till  the  teeth  begin  to  be  formed';  since  it  grows  along 
with  the  teeth,  and  is  absorbed  and  carried  clean  away  when 
in  old  age  the  teeth  fall  out.  The  sides  of  the  sockets  in  which 
the  teeth  are  lodged  are  extremely  thin,  and  surround  them 
closely.  The  teeth  are  so  closely  embraced  by  their  sockets, 
and  we  are  so  far  from  being  possessed  of  any  instrument  by 
which  they  can  be  pulled  perpendicularly  out,  that  the  sockets 
can  seldom  escape  ; they  are  broken  or  splintered  in  perhaps 
one  of  four  extractions,  even  by  the  most  dexterous  artists  in 
that  line. 

The  PALATE  process  is  a plate  of  bone  which  divides  the 
nose  from  the  mouth,  constituting  the  roof  of  the  palate,  and 
the  floor  or  bottom  of  the  nostrils.  This  plate  is  thinner  in 
its  middle,  and  thicker  at  either  edge  : thus,  it  is  thick  where 
it  first  comes  olf  from  the  alveolar  process : it  is  thin  in  its 


OF  THE  FACE  AND  JAWS. 


61 


middle  ; and  it  is  again  thick  where  it  meets  its  fellow  of  the 
opposite  side.  For  at  the  place  where  the  two  upper  jaw- 
bones meet,  the  palate-plate  is  turned  upwards,  so  that  the 
two  hones  are  opposed  to  each  other  in  the  middle  of  the 
palate  by  a broad  flat  surface,  which  cannot  he  seen  but  b\" 
separating  the  bones.  This  surface  is  so  very  rough,  that  the 
middle  palate  suture  almost  resembles  the  sutures  of  the  skull ; 
and  the  maxillary  bones  are  neitlier  easily  separated,  nor  easi- 
ly joined  again.  This  meeting  of  the  palate-plates  by  a broad 
surface,  makes  a rising  spine,  or  sharp  ridge,  towards  the  nos- 
trils, so  that  the  broadness  of  the  surface  by  which  these  bones 
meet,  serves  a double  purpose ; it  joins  the  bones  securely, 
and  it  forms  a small  ridge  upon  which  the  split  edge  of  the  vo- 
mer, or  partition  of  the  nose,  is  planted.  Thus  we  find  the 
palate-plate  of  the  maxillary  bones  conjoined,  forming  almost 
the  whole  of  the  palate,  while  what  are  properly  called  the 
palate-bones  form  a very  small  share  of  the  back  part  only.  As 
these  thinner  bones  of  the  face  have  no  marrow,  they  are 
nourished  by  their  periosteum  only ; they  are  of  course  per- 
forated w'ith  many  small  holes.  A great  many  minute  holes 
are  found  along  the  palate-plate,  about  the  place  of  the  sock- 
ets, and  indeed  all  over  the  maxillary  bones ; and  this  is 
particular  in  the  palate,  that  the  hard  membrane,  or  covering 
of  it,  is  fixed  to  the  bony  plate  by  many  rough  tubercles,  and 
even  by  small  hooks,  which  are  easily  found  in  the  dried  bone. 

Since  we  are  describing  the  plates  of  the  bone  as  processes, 
we  ought  to  enumerate  the  facies  interna  nasalis  as  an  inter- 
nal NASAL  PLATE.  This  is  the  side  of  the  bone  which  is  to- 
wards the  cavity  of  the  nose,  on  which  the  lower  spongy  bone 
hangs,  and  which  is  perforated  to  allow  a communication  be- 
twixt the  great  cell  and  the  nose. 

The  ANTRUivi  MAXiLLAHE,  Or  cavity  of  the  jaw-bone,  is  com- 
monly named  antrum  highmorianum,  after  its  discoverer, 
Highmore.  We  have  gone  round  the  antrum  on  all  its  sides, 
in  describing  these  processes  of  the  bone : the  palate-plate 
makes  the  floor  of  the  antrum ; the  orbitary  process  makes  its 
roof ; the  cheek  quite  up  from  the  sockets  of  the  teeth  to  the 
lower  part  of  the  eye,  forms  its  walls  or  sides  : so  that  when  the 
antrum  enlarges,  it  is  the  cheek  that  becomes  deformed ; and 
when  we  design  to  open  the  antrum,  we  either  perforate  the 
cheek,  or  pull  one  of  the  teeth.  The  antrum  is  round  towards 
the  cheek,  but  it  has  a flat  side  towards  the  nose ; it  is  divided 
fri>ai  the  caviiy  of  the  nostril  by  a flat  and  very  thin  plate  of 
bone  ; it  seems  in  the  naked  skull  to  have  a very  wide  ope- 
ning ; but  in  the  skull,  covered  with  its  soft  parts,  we  find  the 
antrum  almost  closed  by  a membrane  which  stretches  over  the 


62 


OF  THE  BOiNES 


opening,  and  leaves  but  one  or  two  very  small  holes,  of  the 
size  of  tbe  smallest  pea,  by  which,  perhaps,  the  reverberation 
of  sound  in  the  antrum  is  more  elfectual  in  raising  the  voice, 
and  by  which  small  hole,  the  mucus,  which  is  secreted  in  the 
antrum,  drops  out  into  the  nose.  The  cavity  of  the  antrum, 
like  the  inner  surfaces  of  the  nostrils,  is  covered  with  a mem- 
brane, and  is  bedewed  with  mucus ; and  the  mucus  drops  more 
or  less  freely  in  various  positions  of  the  head.  Sometimes  by 
cold  or  other  accidents,  inflammations  and  swellings  of  the 
membrane  come  on ; the  holes  are  closed  ; the  drain  of  mat- 
ter is  suppressed  and  confined  within,  and  the  cheek  swells. 
Perhaps  there  may  be  some  particular  disease  of  the  mem- 
brane with  which  the  cavity  is  lined,  or  of  the  bone  itself:  in 
one  way  or  other,  diseases  of  this  cavity,  and  collections  of 
matter,  dreadful  pain  and  caries  of  the  bone,  are  very  frequent: 
then  the  cheek  rises;  the  face  is  irrecoverably  deformed. 
Sometimes  the  matter  makes  its  way  by  the  sides  of  the  teeth, 
or  at  last  it  bursts  through  the  bones,  makes  an  ulcer  in  the 
cheek  ; and  then  there  is  a natural  cure,  but  slow  and  uncer- 
tain. There  is  no  very  sure  mark  of  this  disease  ; it  may  be 
known  by  an  attentive  retrospect  of  all  the  circumstances. 
The  disease  is  not  to  be  easily  nor  certainly  discovered  ; but 
a very  long  continued  tooth-ache,  an  uncommon  degree  of 
pain  or  greater  affection  of  the  eye,  with  a swelling  and  redness 
and  gradual  rising  of  the  cheek,  are  very  suspicious  signs. 
The  pulling  of  the  second  or  third  of  the  grinding  teeth,  often 
brings  a splinter  away  with  it,  which  opens  a road  for  the  mat- 
ter to  flow ; or  though  there  be  no  breach  of  the  socket,  often 
the  confined  matter  follows  the  tooth,  because  not  unfrequent- 
ly  the  longer  fangs  of  the  grinders  naturally  penetrate  quite 
into  this  cavity  of  the  jaw:  if  the  matter  should  not  flow,  the 
floor  of  the  antrum  is  easily  perforated,  by  introducing  a sharp 
stillet  by  the  socket  of  the  tooth  that  is  pulled.  The  flow  of 
the  matter  gives  relief,  and  injections  complete  the  cure.  But 
as  this  opening  is  sometimes  a cure,  it  is  sometimes  also  a 
disease  ; for  the  breaking  of  a socket,  sometimes  opening  a 
way  into  this  antrum,  there  follows  inflammation  of  its  internal 
surface,  a running  of  matter,  and  sometimes  caries  of  the 
bone. 

Holes. — There  is  only  one  perfect  hole  in  this  bone  ; but, 
by  its  union  with  other  bonesi  it  forms  four  more  : The  infra- 
orbitary hole,  for  transmitting  the  infra-orbitary  nerve  from 
the  bottom  of  the  eye,  is  the  opening  of  the  canal  which 
comes  along  under  the  eye.  It  is  just  under  the  margin  of  the 
orbit,  or  sometimes  the  nerve  which  it  transmits,  divides,  and 
nialies  two  smaller  holes  in  its  passage  upon  the  cheek.  A 


OF  THE  FACE  AND  JAWS. 


63 


hole  in  the  palate-plate,  which  belongs  equally  to  each  of  the 
palate-bones  may  be  counted  the  second  foramen ; for  it  ig 
betwixt  the  two  bones  in  the  fore  part,  or  beginning  of  the 
palate-suture  behind  the  two  first  cutting  teeth.  This  hole 
is  named  forajMEN  incisivum,  as  opening  just  behind  the  inci- 
sive or  cutting  teeth  ; or  it  is  named  anterior  palatine  hole, 
to  distinguish  it  from  one  in  the  back  of  the  palate.  This  hole 
is  large  enough  to  receive  the  point  of  a quill  ; it  is  single  to- 
wards the  mouth  ; but  towards  the  nose,  it  has  two  large  ope- 
nings, one  opening  distinctly  into  each  nostril. 

But  it  will  be  well  to  explain  here  a third  hole,  which  is 
common  to  the  maxillary,  with  the  proper  palate-bones.  It  is 
formed  on  the  back  part  of  the  palate  (one  on  either  side,)  in 
the  suture  which  joins  the  palate-bones  to  the  jaw-bones : it  is 
named  posterior  palatine  hole  : It  is  as  large  as  the  ante- 
rior palatine  hole,  but  it  serves  a much  more  important  pur- 
pose ; for  the  upper  maxillary  nerve  sends  a large  branch  to 
the  palate,  which  branch  comes  down  behind  the  back  of  the 
nostril,  perforates  the  back  of  the  palate  by  the  posterior  pala- 
tine hole,  and  then  goes  forward  in  two  great  branches  along 
the  palate.  Thus  the  chief,  or,  we  might  say,  the  only  nerves 
of  the  palate  comes  down  to  it  through  these  posterior  palatine 
holes.  The  use  of  the  anterior  palatine  hole  has  long  been  a 
a problem.  It  looks  almost  as  if  it  were  merely  designed  for 
giving  the  soft  palate  a surer  hold  upon  the  bone  ; but  Scarpa, 
the  Italian  anatomist,  describes  a nerve  from  the  5th  pair,  ta- 
king its  course  in  this  way  to  the  soft  palate. 

The  fourth  foramen  is  formed  by  the  union  of  the  lower 
spongy  bone,  to  the  internal  nasal  plate  of  the  bone  ; and  is 
for  the  transmission  of  the  lachrymal  duct. 

The  LATERAL  ORBITARY  FISSURE,  Called  alsO  SPHENO  MAX- 
ILLARY FISSURE,  is  a slit  formed  by  this  bone  and  the  sphenoid 
bone  ; it  is  a communication  betwixt  the  orbit  and  temple. 

The  whole  surface  of  the  bone  which  forms  the  antrum  is 
perforated  with  frequent  small  holes,  especially  towards  its 
back  part,  transmitting  small  arteries  and  nerves  to  the  teeth  ; 
and  the  back  part  of  the  antrum  forms  with  the  orbitary  part 
of  the  sphenoid  bone  a second  foramen  lacerum  for  the  orbit, 
which  is  an  irregular  opening  tow'ards  the  bottom  of  the  socket, 
and  is  for  the  accumulation  of  fat,  rather  than  for  the  trans- 
mission of  nerves  j and  it  is  from  the  wasting  of  this  fat,  taken 
back  into  the  system,  that  the  eye  sinks  so  remarkably  in  fe- 
vers, consumptions,  and  such  other  diseases  as  waste  the  body. 
At  the  termination  of  the  alveolar  circle,  backwards,  there  are 
two  or  three  holes,  into  which  the  branches  of  the  internal 
maxillary  artery  enter,  which  go  to  supply  the  teeth  of  the  up- 


64 


OF  THE  BONES 


per  jaw.  There  is  a trifling  hole  for  the  transmission  of  an 
artery  on  the  nasal  plate  of  this  bone. 

The  OSSA  PALATI,  OR  PALATE  BONES — are  very 
small,  but  have  such  a number  of  parts,  and  such  curious  con- 
nections as  are  not  easily  explained.  They  seem  to  eke  out 
the  superior  maxillary  bones,  so  as  to  lengthen  the  palate,  and 
complete  the' nostrils  behind:  they  even  extend  upwards  into 
the  socket,  so  as  to  form  a part  of  its  circle ; although,  in 
looking  for  them  upon  the  entire  skull,  all  these  parts  are  so 
hidden,  that  we  should  suppose  the  palate-bones  to  be  of  no 
greater  use  nor  extent  than  to  lengthen  the  palate  a little 
backwards. 

The  parts  of  the  palate-bone  are  these  : 

The  PALATAL  PLATE,  OP  process  of  the  palate-bone,  whence 
it  has  its  name,  lies  horizontal  in  the  same  level  with  the  pala- 
tal process  of  the  jaw-bone,  which  it  resembles  in  its  rough 
and  spinous  surface  ; in  its  thinness  ; in  its  being  thinner  in  the 
middle,  and  thicker  at  either  end  ; in  its  being  opposed  to  its 
fellow  by  a broad  surface,  which  completes  the  middle  palate 
SUTURE  ; and  it  is  connected  with  the  palate  process  of  the 
jaw,  by  a suture  resembling  that  by  which  the  opposite  bones 
are  joined  ; but  this  suture,  going  across  the  back  part  of  the 
palate,  is  named  the  transverse  palate  suture.  Where  the 
two  palate-bones  are  joined,  they  run  backwards  into  an  acute 
point ; on  either  side  of  that  middle  point,  they  make  a semi- 
circular line,  and  again  run  out  into  two  points  behind  the 
grinding  teeth  of  each  side.  By  this  figure  of  the  bones,  the 
back  line  of  the  palate  has  a scolloped  or  waved  form  The 
velum  palati,  or  curtain  of  the  palate,  is  a little  arched,  fol- 
lowing the  general  line  of  the  bones;  the  uvula,  or  pap,  hangs 
exactly  from  the  middle  of  the  velum  taking  its  origin  from 
the  middle  projecting  point  of  the  two  bones ; and  a small 
muscle,  the  azygus  uvulae,  runs  down  in  the  middle  of  the  ve- 
lum, taking  its  origin  from  this  middle. 

The  small  projecting  point  of  the  palate-bone,  just  behind  the 
last  grinding  tooth,  touches  the  pterygoid  process  of  the  sphe- 
noid bone,  it  is  therefore  named  the  pte  ygoid  proce^'S  of 
the  palate-bone : but  it  is  so  joined  with  the  pterygoid  process 
of  the  sphenoidal  bone,  that  they  are  not  to  he  distinguished 
in  the  entire  skull  The  posterior  pterygoid  hole,  or  third 
hole  of  the  palate,  is  just  before  this  point. 

The  NASAL  PLATE,  or  PROc  ss,  is  a thin  and  single  plate  ; 
rises  perpendicularly  upwards  from  the  palate;  lies  upon  the 
side  a/id  back  part  of  tlie  nostrils,  so  as  to  form  their  opening 
backwards  into  the  throat ; it  is  so  joined  to  the  upper  jaw- 


OP  THE  FACE  AND  JAWS, 


66 


bone,  that  it  lies  there  like  a sounding-board  upon  the  side  of 
the  antrum  Highmorianum,  and  completes  that  cavity  forming 
the  thin  partition  betwixt  it  and  the  nose. 

This  nasal  process  extends  thus  up  from  the  back  arch  of 
the  palate  to  the  back  part  of  the  orbit;  and,  though  the  nasal 
plate  is  very  thin  and  delicate  in  its  whole  length,  yet,  where  it 
enters  into  the  orbit,  it  is  enlarged  into  an  irregular  kind  of  knob 
of  a triangular  form.  This  knob  is  named  its  orbitaky  pro- 
cess ; or,  as  the  knob  has  two  faces  looking  two  ways  in  the  or- 
bit, it  is  divided  sometimes  (as  by  Monro  the  father),  into  two 
orbitary  processes,  the  anterior  and  posterior ; the  anterior  one 
is  the  chief.  This  orbitary  process,  or  point  of  the  palate-bone, 
being  triangular,  very  snmll,  and  very  deep  in  the  socket,  is  not 
easily  discovered  in  the  entire  skull. 

This  orbitary  pjocess  is  most  commonly  hollow  or  cellular, 
and  its  cells  are  so  joined  to  those  of  the  sphenoid  bone,  that 
it  is  the  palate-bone  that  shuts  the  sphenoid  cells,  and  the  sphe- 
noid and  palatine  cells  of  each  side  constitute  but  one  ge- 
neral cavity. 

On  the  inside  of  the  nasal  plate  of  this  bone,  we  may  per- 
ceive a ridge  corresponding  with  that  on  the  nasal  process  of 
the  maxillary  bone,  and  which  is  for  giving  attachment  to  the 
lower  spongy  bone. 

The  OSSA  SPONGIOSA,  or  TURBINATA  INFERI- 
ORA,  are  so  named,  to  distinguish  them  from  the  upper 
spongy  bones,  which  belong  to  the  os  lethmoides;  but  these 
lower  spongy  bones,  are  quite  distinct,  formed  apart,  and  con- 
nected in  a very  slight  way  with  the  upper  jaw-bones. 

The  OSSA  SPONGIOSA  iNFERioRAare  two  bones,  much  rolled 
or  convoluted,  very  spongy,  much  resembling  puff-paste,  having 
exactly  such  holes,  cavities,  and  net-work,  as  we  see  in  raised 
paste,  so  that  they  are  exceedingly  light.  They  lie  rolled  up, 
in  the  lower  part  of  the  nose;  are  particularly  large  in  sheep; 
are  easily  seen  either  in  the  entire  subject  or  in  the  naked  skull. 
Their  point  forms  that  projection  which  we  touch  with  the 
finger  in  picking  the  nose ; and  from  that  indecent  practice, 
very  often  serious  consequences  arise ; for  in  many  instances, 
polypi  of  the  lower  spongy  bones,  which  can  be  fairly  traced  to 
hurts  of  this  kind,  grow  so  as  to  extend  down  the  throat, 
causing  suffocation  and  death. 

One  membrane  constitutes  the  universal  lining  of  the  cavi- 
ties of  the  nose,  and  the  coverings  of  all  the  spongy  bones. 
This  continuity  of  the  membrane  prevents  our  seeing  in  the 
subji  ct  how  slightly  the  spongy  bones  are  hung  : but  in  the  bare 
and  dissected  skull  we  find  a neat  small  hook  upon  the  spongy 


66 


OF  THE  BONES 


bone,  by  which  it  is  hung  upon  the  edge  of  the  antrum  maxil- 
lare  ; for  this  lower  spongy  bone  is  laid  upon  the  side  of  the 
antrum,  so  as  to  help  the  palate-bone  in  closing  or  covering 
that  cavity  from  within.  One  end  of  the  spongy  bone,  rather 
more  acute,  is  turned  towards  the  opening  of  the  nostril,  and 
covers  the  end  of  the  lachrymal  duct : the  other  eni>  of  the 
same  bone  points  backwards  towards  the  throat.  The  curling 
plate  hangs  down  into  the  cavity  of  the  nostril,  with  its  arched 
side  towards  the  nose.  This  spongy  bone  differs  from  the  spon- 
gy process  of  the  sethmoid  bone,  in  being  less  turbinated  or 
complex,  in  having  no  cells  connected  with  it,  and  perhaps  it 
is  less  directly  related  to  the  organ  of  smell.  If  pol)pi  arise 
from  the  upper  spongy  bone,  we  can  use  less  freedom,  and 
dare  hardly  pull  them  away,  for  fear  of  injuring  the  cribriform 
plate  of  the  sethmoid  bone.  We  are  indeed  not  absolutely  pro- 
hibited from  pulling  the  polypi  from  the  upper  spongy  bone ; 
but  we  are  more  at  ease  in  pulling  them  from  the  lower  one, 
since  it  is  quite  an  insulated  bone.  When  peas,  or  any  such 
foreign  bodies,  are  retained  in  the  nose,  it  must  be  from  swell- 
ing, and  being  detained,  among  the  spongy  bones. 

The  spongy  bones  are  not  absolutely  limited  in  their  num- 
ber; there  is  sometimes  found  bewitxt  these  two  a third  set  of 
small  turbinated  bones,  commonly  belonging  to  the  sethmoid 
bone. 

VOMER. — The  nose  is  completed  by  the  vomer,  which  is 
named  from  its  resemblance  to  a plough-share,  and  which  di- 
vides the  two  nostrils  from  each  other:  It  is  a thin  and  slen- 
der bone,  consisting  evidently  of  two  plates,  much  compres- 
sed together,  very  dense,  and  strong,  but  still  so  thin  as  to  be 
transparent.  The  two  plates  of  which  the  vomer  is  composed 
split  or  part  from  each  other  at  every  edge  of  it,  so  as  to  form 
a groove  on  every  side.  1.  On  its  upper  part,  or,  as  we  may 
call  it,  its  base,  by  which  it  is  fixed  to  the  skull,  the  vomer 
has  a WIDE  groove,  receiving  the  projecting  point  of  the  aeth- 
moid  and  sphenoid  bones  : thus  it  stands  very  firm  and  secure, 
and  capable  of  resisting  very  violent  blows.  2.  Upon  its  low- 
er part  its  groove  is  narrower,  and  receives  the  rising  line  in 
the  middle  of  the  palate-plate,  where  the  bones  meet  to  form 
the  palate  suture.  At  its  forepart  it  is  united  by  a ragged  sur- 
face, and  by  something  like  a groove  to  the  middle  cartilage 
of  the  nose ; and,  as  the  vomer  receives  the  other  bones  into 
its  grooves,  it  is  in  a manner  locked  in  on  all  sides:  it  re- 
ceives support  and  strength  from  each  ; and  if  the  vomer  and 
its  cartilage  should  seem  too  slender  a support,  for  the  fabric 
of  the  nose,  let  it  be  remembered,  that  they  are  all  firmly 


OF  THE  FACE  AND  JAWS. 


67 


connected,  and  covered  by  one  continuous  membrane,  which 
is  thick  and  strong,  and  that  this  is  as  a periosteum,  or  rather 
like  a continued  ligament,  which  increases  greatly  the  thick- 
ness and  the  strength  of  every  one  of  these  thin  plates.  The 
vomer,  in  almost  every  subject,  bends  much  towards  one  or 
other  nostril,  so  as  sometimes  to  occasion  no  small  apprehen- 
sion, when  it  happens  to  be  first  observed. 

OS  MALAE,  or  the  bone  of  tbe  cheek,  is  easily  known. 
It  is  that  large  square  bone  which  forms  the  cheek : it  has 
four  distinct  points,  which  anatomists  have  chosen  to  demon- 
strate with  a very  superfluous  accuracy.  The  upper  orbita- 
ry PROCESS  stands  highest,  running  upwards  to  form  part  of 
the  socket,  the  outer  corner  of  the  eye,  and  the  sharp  edge  of 
the  temple.  The  inferior  orbitary  process,  which  is  just 
opposite  to  this,  forming  tbe  lower  part  of  the  orbit  and  the  edge 
of  the  cheek.  The  maxillary  process  is  that  broad  and  rough 
surface,  by  which  it  is  joined  to  the  upper  jaw-bone.  The  one 
the  best  entitled  to  the  name  of  process,  because  it  stands  out 
quite  insulated,  and  goes  outwards  and  backwards  to  unite 
with  the  temporal  bone,  forming  the  zygoma  or  temporal  arch, 
is  named  the  zygomatic  process.  The  plate,  which  goes 
backwards  to  form  a part  of  the  orbit,  is  named  the  internal 
orbitary  process,  a small  hole  is  observed  on  the  outer  sur- 
face of  the  bone  which  transmits  an  artery,  and  sometimes  a 
very  small  nerve  from  the  orbit. 

OS  MAXILLAE  INFERIORIS.— The  lower  jaw-bone 
is  likened  to  a horse  shoe,  or  to  a cresent,  or  to  the  letter  U, 
though  we  need  be  under  no  anxiety  about  resemblances,  for 
a form  so  generally  known.  There  is  such  an  infinite  compli- 
cation of  parts  surrounding  the  ja\\^,  of  glands,  muscles,  blood- 
vessels, and  nerves,  that  it  wxre  endless  to  give  even  the  slight- 
est account  of  these.  They  shall  be  reserved  each  for  its  proper 
place,  while  I explain  the  form  of  the  lower  jaw,  in  the  most 
simple  and  easy  way.  The  lower  jaw  is  divided  into  the  chin, 
viz.  the  space  betwixt  the  two  mental  foramina ; the  base, 
properly  the  sides,  extending  backward  to  the  angle  ; and  the 
upright  portion  of  the  bone. 

The  forepart,  or  chin,  is,  in  a handsome  and  manly  face, 
very  square ; and  this  portion  is  marked  out  by  this  square- 
ness, and  by  two  small  holes,  one  on  either  side,  by  which  the 
nerves  of  the  lower  jaw  come  out  upon  the  face. 

The  base  of  the  jaw  is  a straight  and  even  line,  terminating 
the  outline  of  the  face.  It  is  distinctly  traced  all  along,  from 
the  first  point  of  the  chin,  backwards  to  the  angle  of  the  jaw. 
Fractures  of  this  bone,  are  always  more  or  less  transverse,  and 
are  easily  known  by  the  falling  down  of  one  part  of  this  even 


68 


OP  THE  BONES 


line,  and  by  feeling  the  crashing  hones  when  the  fallen  part  is5 
raised.  Such  fractures  happen  from  blows  or  falls  ; but  not 
by  pulling  teeth,  for  the  sockets  of  the  teeth  bear  but  a small 
proportion  to  the  rest  of  the  jaw  ; even  in  children  this  cannot 
happen  ; for  in  them  the  teeth  have  shorter  roots,  and  have  no 
hold  nor  dangerous  power  over  the  jaw  : though  (as  I have 
said)  the  sockets  often  suffer,  the  jaw  itself  never  yields. 

The,  angle  of  the  jaw  is  that  corner  where  the  base  of  the 
jaw  ends,  where  the  bone  rises  upwards,  at  right  angles,  to  be 
ai  liculated  with  the  head.  This  part,  also,  is  easily  felt,  and 
by  it  we  judge  well  of  the  situation  of  veins,  arteries,  and 
glands  which  might  be  in  danger  of  being  cut,  in  wounds  or  in 
operations.  There  are  two  processes  of  the  jaw  of  particular 
importance,  the  coronoid  or  horn-like  process,  for  the  inser- 
tion of  its  strong  muscles,  especially,  of  the  temporal  muscle, 
and  the  condy  loid  or  hinge  process,  by  which  it  is  joined  with 
the  temporal  bone. 

The  couoNoin  process,  named  from  its  resemblance  tp  a 
horn,  is,  like  the  rest  of  the  jaw-bone,  flat  on  its  sides,  and 
turned  up  with  an  acute  angle,  very  sharp  at  its  point,  and 
when  the  bone  is  in  its  place,  lying  exactly  under  the  zygoma 
or  temporal  arch.  The  temporal  muscle  runs  under  this  arch, 
and  lays  hold  on  the  coronary  process,  not  touching  it  on  one 
point  only,  but  grasping  it  on  every  side,  and  all  round.  And 
the  process  is  set  so  far  before  the  articulation  of  the  jaw,  that 
it  gives  the  muscle  great  power.  This  process  is  so  defended 
by  the  temporal  arch,  and  so  covered  by  muscles  that  it  cannot 
be  felt  from  without. 

The  CONDYLOID  PROCESS,  or  the  articulating  proccss  of  the  jaw 
is  behind  this.  This  also  is  of  the  same  flat  form  with  the  rest 
of  the  jaw.  The  condyle,  or  joint  of  the  jaw-bone,  is  placed 
upon  the  top  of  the  rising  branch.  The  condyle,  or  articula- 
ting head,  is  not  round,  but  fiat,  of  a long  form,  and  set  across 
the  branch  of  the  jaw.  This  articulating  process  is  received 
into  a long  hollow  of  the  temporal  bone,  just  under  the  root  of 
the  zygomatic  process  ; so  that  by  the  long  form  of  the  con- 
dyles, and  of  the  cavity  into  which  it  is  received,  this  joint  is  a 
mere  hinge,  not  admitting  of  lateral  nor  rotatory  motions,  at 
least  of  no  wider  lateral  motions  than  those  which  are  necessa- 
ry in  grinding  the  food  ; but  the  hinge  of  the  jaw  is  a complex 
and  very  curious  one,  which  shall  be  explained  in  its  proper 
place.  The  line  of  continuation  between  these  two  last  pro- 
cesses forms  what  is  called  the  semilunar  notch. 

The  ALVEOLAR  PROCESS,  OP  the  long  range  of  sockets  for  the 
teeth,  resembles  that  of  the  upper  jaw.  The  jaw,  as  the  body 
grows,  is  slowly  increasing  in  length,  and  the  teeth  are  added 


OF  THE  FACE  AMD  JAWS. 


69 


in  proportion  to  the  growth  of  the  jaws.  When  the  jaws  have 
acquired  their  full  size,  the  sockets  are  completely  filled  ; the 
lips  are  extended,  and  the  mouth  is  truly  formed.  In  the  de- 
cline of  life  the  teeth  fall  out,  and  the  sockets  are  re-absorbed, 
and  carried  clean  away,  as  if  they  had  never  been  ; so  that  the 
chin  projects,  the  cheeks  become  hollow,  and  the  lips  fall  in, 
the  surest  marks  of  old  age. 

The  SPINA  INTERNA,  01’  internal  tubei*cle  of  the  lower  jaw, 
is  just  behind  the  symphysis,  or  on  Ae  inside  of  the  circle  of 
the  chin.  It  gives  origin  to  muscles  which  move  the  tongue 
and  larynx.  On  the  inside  of  the  lateral  portion  of  the  jaw, 
we  observe  an  oblique  ridge  for  the  attachment  of  the  rnylo 
hyoideus.  On  the  inside  of  the  angle,  the  bone  is  rough  for 
the  attachment  of  the  pterygoid  muscle. 

The  successive  changes  of  the  form  of  the  jaw  are  worthy 
of  being  mentioned  once  more  ; first,  that  in  the  child  the  jaw 
consists  of  two  bones,  which  are  joined  slightly  together  in 
the  chin.  This  joining,  or  symphysis,  as  it  is  called,  is  easily 
hurt,  so  that  in  preternatural  labours  it  is,  according  to  the 
common  method  of  pulling  by  the  chin,  always  in  danger, 
and  often  broken.  During  childhood  the  processes  are  blunt 
and  short,  do  not  turn  upwards  with  a bold  and  acute  angle, 
but  go  off  obliquely  from  the  body  of  the  bone.  The  teeth 
are  not  rooted,  but  sticking  superficially  in  the  alveolar  pro- 
cess ; and  another  set  lies  under  them  ready  to  push  them' 
from  the  jaws. 

Secondly,  That  in  youth  the  alveolar  process  is  extending, 
the  teeth  are  increasing  in  number.  The  coronoid  and  arti- 
culating processes  are  growing  acute  and  large,  and  are  set  off 
at  right  angles  from  the  bone.  The  teeth  are  now  firmly  root- 
ed ; for  the  second  set  has  come  up  from  the  body  of  the 
jaw. 

Thirdly,  In  manhood  the  alveolar  process  is  still  more  elong- 
ated. The  dentes  sapienthe  are  added  to  the  number  of 
the  teeth  ; but  often,  by  this,  the  jaw  is  too  full,  and  this  last 
tooth  coming  up  from  the  backmost  point  of  the  alveolar  pro- 
cess in  either  jaw,  it  sometimes  happens  that  the  jaw  cannot 
easily  close ; the  new  tooth  gives  pain  ; it  either  corrupts,  or 
it  needs  to  be  drawn. 

Fourthly,  In  old  age  the  jaw  once  more  falls  flat ; it  shrinks 
according  to  the  judgment  of  the  eye,  to  half  its  size ; the 
sockets  are  absorbed,  and  conveyed  away  ; and  in  old  age  the 
coronoid  process  rises  at  a more  acute  angle  from  the  jaw- 
bone, and  by  the  falling  down  of  the  alveolar  process,  the  coro- 
Boid  process  seems  increased  in  length. 


70 


OF  THE  TRUNK. 


HOLES. — The  holes  of  the  jaw  are  chiefly  two  : 

A LARGE  HOLE  Oil  the  inner  side,  and  above  the  angle  of 
the  jaw,  just  at  the  point  where  these  two  branches,  the  con- 
dyloid and  the  coronoid  processes  part.  A wide  groove,  from 
above  downwards,  leads  to  the  hole ; and  the  hole  is,  as  it 
were,  defended  by  a small  point,  or  pike  of  bone,  rising  up 
from  its  margin.  This  is  the  great  hole  for  admitting  the 
LOWER  MAXILLARY  NERVE  into  the  hollow  of  the  jaw,  where  it 
goes  round  within  the  circle  of  the  jaw,  distributing  its  nerves 
to  all  the  teeth.  But  at  the  point  where  this  chief  branch  of 
the  nerve  goes  down  into  the  jaw,  another  branch  of  the  nerve 
goes  forward  to  the  tongue.  And  as  nerves  make  an  impres- 
sion as  deep  as  that  of  arteries  in  a bone,  we  find  here  two 
grooves,  first,  one  marking  the  great  nerve,  as  it  advances  to- 
wards its  hole  ; and,  secondly,  a smaller  groove,  marking  the 
course  of  the  lesser  branch,  as  it  leaves  the  trunk,  and  passes 
this,  hole  to  go  forward  to  the  tongue. 

Along  with  this  nerve,  the  lower  maxillary  artery,  a large 
branch  enters  also  by  the  hole;  and  both  the  nerve  and  the 
artery,  after  having  gone  round  the  canal  of  the  jaw,  emerge 
again  upon  the  chin. 

The  second  hole  of  the  lower  jaw  is  that  on  the  side  of  the 
chin,  which  permits  the  remains  of  the  great  nerve  and  artery 
(almost  expended  upon  the  teeth)  to  come  out  upon  the  chin ; 
it  is  named  the  mental  hole. 


CHAP.  V. 

OF  THE  BONES  OF  THE  TRUNK;  OR,  OF  THE  SPINE,  THORAX, 
AND  PELVIS. 

The  spine  is  so  named  from  certain  projecting  points  of 
each  bone,  which,  standing  outwards  in  the  back,  form  a con- 
tinued ridge  ; and  the  appearance  of  continuity  is  so  complete, 
that  the  whole  ridge  is  named  spine,  which,  in  common  lan- 
guage, is  spoken  of  as  a single  bone.  This  long  line  consists 
of  twenty-four  distinct  bones,  named  vertebrae,  from  the  Latin 
vertere,  to  turn.  They  conduct  the  spinal  marrow,  secure 
from  harm  the  whole  length  of  the  spine,  and  support  the 
whole  weight  of  the  trunk,  head,  and  arms ; they  perform,  at 
certain  points,  the  chief  turnings  and  bendings  of  the  body ; 


OF  THE  TRUNK. 


71 


and  do  not  suffer  under  the  longest  fatigue,  or  the  greatest 
weight  which  the  limbs  can  bear.  Hardly  can  any  thing  be 
more  beautiful  or  surprising  than  this  mechanism  of  the  spine, 
where  nature  has  established  the  most  opposite  and  inconsist- 
ent functions  in  one  set  of  bones ; for  these  bones  are  so  free 
in  motion,  as  to  turn  continually,  yet  so  strong  as  to  support 
the  whole  weight  of  the  body ; and  so  flexible  as  to  turn  quick- 
ly in  all  directions,  yet  so  steady  within,  as  to  contain  and  de- 
fend the  most  material  and  the  most  delicate  part  of  the 
nervous  system. 

The  vertebrae  are  arranged  according  to  the  neck,  back, 
and  loins,  and  the  number  of  pieces  corresponds  with  the 
length  of  these  divisions.  The  vertebrse  of  the  loins  are  live 
in  number,  very  large  and  strong,  and  bearing  the  whole  weight 
of  the  body.  Their  processes  stand  out  very  w'ide  and  free, 
not  entangled  with  each  other,  and  performing  the  chief  mo- 
tions of  the  trunk.  The  vertebrse  of  the  back  are  twelve  in 
number.  They  also  are  big  and  strong,  yet  smaller  than  those 
of  the  loins their  processes  are  laid  over  each  other;  each 
bone  is  locked  in  with  the  next,  and  embarrassed  by  its  con- 
nection with  the  ribs ; this  is,  therefore,  the  steadiest  part  of 
the  spine,  a very  limited  motion  only  is  allowed.  The  verte- 
bra of  the  NECK  are  seven  in  number;  they  are  more  simple, 
and  like  rings ; their  processes  hardly  project ; they  are  very 
loose  and  free ; and  their  motions  are  the  widest  and  easiest  of 
all  the  spine. 

The  seven  vertebra;  of  the  neck,  twelve  of  the  back,  and 
five  of  the  loins,  make  twenty-four  in  all,  which  is  the  regular 
proportion  of  the  spine.  But  the  number  is  sometim'es  chang- 
ed, according  to  the  proportions  of  the  body;  for,  where  the 
loins  are  long,  there  are  six  vertebrre  of  the  loins,  and  but 
eleven  in  the  back ; or  the  number  of  the  pieces  in  the  back 
is  sometimes  increased  to  thirteen  ; or  the  neck,  according  as 
it  is  long  or  short,  sometimes  has  eight  pieces,  or  sometimes 
only  six. 

The  general  form,  processes,  and  parts  of  the  vertebra,  are 
best  exemplified  in  the  vertebra  of  the  loins ; for  in  it  the  body 
is  large,  the  processes  are  right-lined,  large,  and  strong ; the 
joint  is  complete,  and  all  its  parts  are  very  strongly  marked. 
Every  vertebra  consists  of  a body,  which  is  firm  for  supporting 
the  weight  of  the  body,  and  hollow  behind,  for  transmitting 
the  spinal  marrow;  of  two  articulating  processes  above,  and 
two  below,  by  which  it  is  jointed  with  the  bones  which  are 
above  and  below  it ; of  two  transverse  processes,  which  stand 
out  from  either  side  of  the  bone,  to  give  hold  and  purchase  to 
those  muscles  which  turn  the  spine  ; and  of  one  process,  the 


72 


OF  THE  TRUNKi 


spinous  process,  which  stands  directly  backwards  from  the 
middle  of  the  bone  ; and  these  processes  being  felt  in  distinct 
points  all  the  way  down  the  back,  gi\  e the  whole  the  appear- 
ance of  a ridge  ; whence  it  has  the  name  of  spine. 

The  BOOY  of  the  vertebra  is  a large  mass  of  soft  and  spongy 
bone ; it  is  circular  before,  and  flat  upon  the  sides.  It  is 
hollowed  into  the  form  of  a crescent  behind,  to  give  the  shape 
of  that  tube  in  which  the  spinal  marrow  is  contained.  The 
body  has  but  a very  thin  scaly  covering  for  its  thick  and  spon- 
gy substance.  It  is  tipped  with  a harder  and  prominent  ring 
above  and  below,  as  a sort  of  defence,  and  within  the  ring,  the 
body  of  the  vertebra  is  hollowed  out  into  a sort  of  superficial 
cup,  which  receives  the  ligamentous  substance  by  which  the 
two  next  vertebrae  are  joined  to  it ; so  that  each  vertebra  goes 
upon  a pivot,  and  resembles  the  ball  and  socket  joints.  And 
in  many  animals  it  is  distinctly  a joint  of  this  kind. 

On  the  fore  and  back  part  of  the  body  of  the  vertebra  are 
several  holes  which  are  for  the  transmission  of  blood-vessels 
and  for  the  attachment  of  ligaments. 

The  BODY  is  the  main  part  of  the  vertebra  to  which  all  the 
other  processes  are  to  be  referred ; it  is  the  centre  of  the 
spine,  and  bears  chiefly  the  weight  of  the  body  : it  is  large  in 
the  loins  where  the  weight  of  the  whole  rests  upon  it,  and 
where  the  movements  are  rather  free  : it  is  smaller  in  the 
veftebrffi  of  the  back,  where  theje  is  almost  no  motion  and  less 
w'eight ; and  in  the  vertebrae  of  the  neck,  there  is  hardly  any 
body ; the  vertebrae  being  joined  to  each  other  chiefly  by  the 
articulating  processes. 

The  ring  or  circle  of  bone  or  the  arch  which,  together  with 
the  body  itself,  forms  this  circle,  next  attracts  our  notice,  for 
the  arches  of  the  vertebra,  forming  a continued  tube,  give 
passage  to  the  spinal  marrow.  We  observe  a notch  on  each 
side  of  the  arch  for  transmitting  the  nerves  which  go  out  from 
the  spinal  marrow, 

The  ARTICULATING  PROCESS  is  a small  projection,  standing 
out  obliquely  from  the  body  of  the  vertebra,  with  a smooth 
surface,  by  which  it  is  joined  to  the  articulating  process  of  the 
next  bone ; for  each  vertebra  has  a double  articulation  with 
that  above  and  with  that  below.  The  bodies  of  the  vertebrae 
are  united  to  each  other  by  a kind  of  ligament,  which  forms  a 
more  fixed,  and  rather  an  elastic  joining  ; and  they  art  united 
ag  dll  by  the  articulating  processes,  which  makes  a very  move- 
able  joint  of  the  common  form.  The  articulating  proces.ses 
are  .sometimes  named  oblique  processes,  because  they  stand 
rather  obliquely.  The  upper  ones  are  named  the  ascending 


OF  THE  TRUNK.  73 

oblique  processes,  and  the  two  lower  ones  are  named  the  in- 
ferior or  descending  oblique  processes. 

The  SPINOUS  PROCESSES  are  those  which  project  directly 
backwards,  whose  points  form  the  ridge  of  the  back,  and  whose 
sharpness  gives  the  name  to  the  whole  column.  The  body  of 
each  vertebra  sends  out  two  arms,  which,  meeting  behind, 
form  an  arch  or  canal  for  the  spinal  marrow;  and  fi’om  the 
middle  of  that  arch,  and  opposite  to  the  body,  the  spinous 
process  projects.  Now  the  spinous,  and  the  transverse  proces- 
ses, are  as  so  many  handles  and  levers  by  which  the  spine  is 
to  be  moved,  which,  by  their  bigness,  give  a firm  hold  to  the 
muscles,  and  by  their  length,  give  them  a powerful  lever  to 
work  their  effects  by.  Tlie  spinous  processes,  then,  are  for 
the  insertion  of  these  muscles  which  extend  and  raise  the 
spine. 

The  TRANSVERSE  PROCESSES  Stand  out  from  the  sides  of  the 
arms  or  branches  which  form  this  arch.  They  stand  out  at 
right  angles,  or  transversely  from  the  body  of  the  bone  ; and 
they  also  are  as  levers,  and  long  and  powerful  ones  for  moving 
and  turning  the  spine.  Perhaps  their  chief  use  is  not  for  turn- 
ing the  vertebnx , for  there  is  no  provision  for  much  of  a late- 
ral motion  in  the  lower  part  of  the  spine,  but  the  muscles 
which  are  implanted  into  these,  are  more  commonly  used  in 
assisting  those  which  extend  and  raise  the  spine. 

These  and  all  the  processes,  are  more  distinct,  prominent, 
and  strong ; more  direct  and  larger  in  the  loins,  and  more 
easily  understood  than  in  the  vertebrae  of  any  other  class.  But 
this  prepares  only  for  the  description  of  the  individual  verte- 
bra, where  we  find  a variety  proportioned  to  the  various  offices 
and  to  the  degrees  of  motion  which  each  class  has  to  perform. 

Of  the  vertebra  of  the  loins. — I have  chosen  to  repre- 
sent the  general  form  of  a vertebra,  by  describing  one  from 
the  loins,  because  of  the  distinctness  with  which  all  its  parts 
are  marked.  In  the  lumbar  vertebrae,  the  perpendicular  height 
of  the  body  is  short,  the  intervertebral  substance  is  thicker  in 
the  other  parts  of  the  spine,  and  the  several  processes  stand 
off  from  each  other  distinct  and  clear ; all  which  are  provisions 
for  a freer  motion  in  the  loins.  The  arch  of  the  lumbar  ver- 
tebra is  wider  than  in  the  back,  to  admit  the  looser  texture  of 
the  spinal  marrow. 

The  BODY  of  a lumbar  vertebra  is  particularly  large,  thick, 
and  spongy,  and  its  thin  outer  plate  is  perforated  by  many  ar- 
teries going  inwards  to  nourish  this  spongy  substance  of  the 
bone.  The  length  of  the  body  is  about  an  inch,  and  the  in- 
tersticial  cartilage  is  nearly  as  long;  so  that  the  vertebras  of 
the  loins  present  to  the  eye,  looking  from  within  the  body,  a 

VOL.  j.  K 


74 


OF  THE  TRUNK. 


large,  thick,  and  massy  column,  fit  for  supporting  so  great  a 
weight. 

The  SPINOUS  PROCESS  is  short,  big,  and  strong.  It  runs  hori- 
zontally and  directly  backwards  from  the  arch  of  the  spinal 
marrow.  It  is  flattened,  and  about  an  inch  in  breadth  ; and  it 
is  commonly  terminated  by  a lump  or  knob,  indicating  the 
great  strength  of  the  muscles  which  belong  to  it,  and  the  se- 
cure hold  which  they  have. 

The  TRANSVERSE  PROCESS  is  also  short,  direct,  and  very 
strong,  going  off  horizontally  from  the  side  of  the  bone,  ter- 
minated like  the  spinous,  by  a knotty  point,  where  large  mus- 
cles are  implanted.  We  find  the  spinous  process  divided  into 
two  unequal  parts  by  a spine  from  the  inferior  articulating 
process ; in  the  same  manner  we  see  the  transverse  process 
divided  by  a ridge  extending  from  the  superior  articulating 
process. 

The  ARTICULATING  PROCESSES  of  the  lumbar  vertebrae  stand 
so  directly  upwards  and  downwards,  that  the  name  of  oblique 
processes  cannot  be  applied  here. 

Of  the  VERTEBR®  OF  THE  BACK. — The  character  of  the  ver- 
tebrae of  the  back  is  directly  opposite  to  that  of  the  loins. 
The  BODIES  of  the  vertebrae  are  still  large  to  support  the 
great  weight  of  the  trunk  ; but  they  are  much  longer  than  in 
the  loins,  and  their  intervertebral  substance  is  thin,  for  there 
is  little  motion  here.  The  spinous  processes  in  the  verte- 
brae of  the  back  are  very  long  and  aquiline.  They  are  broad 
at  their  basis,  and  very  small  or  spinous  at  their  further  end  ; 
and  in  place  of  standing  perpendicularly  out  from  the  body, 
they  are  so  bent  down,  that  they  do  not  form  a prominent  nor 
unsightly  spine,  but  are  ranged  almost  in  a perpendicular  line, 
that  is,  laid  over  each  other,  like  the  scales  of  armour,  the 
one  above  touching  the  one  below,  by  which  the  motions  of 
these  vertebra3  are  still  further  abridged  ; and  the  further  to 
sustain  the  column,  there  is  a groove  on  the  under  surface  of 
the  spinous  process,  which  receives  the  superior  edge  of  the 
one  below.  And,  lastly,  the  transverse  processes,  which 
are  short  and  knobby,  in  place  of  standing  free  and  clear  out 
like  those  of  the  loins,  stand  obliquely  backward,  are  tramel- 
led  and  restricted  from  motion,  by  their  connection  with  the 
ribs  ; for  the  ribs  are  not  merely  implanted  upon  the  bodies 
of  the  dorsal  vertebrse,  but  they  are  further  attached  firmly  by 
ligaments,  and  by  a regular  joint  to  the  transverse  process  of 
each  vertebra.  Now  the  rib  being  fixed  to  the  body  of  one 
vertebra,  and  to  the  transverse  process  of  the  vertebra  below, 
the  motions  of  the  vertebra;  are  much  curbed.  And  we  also 
get  another  mark  by  which  the  dorsal  vertebrie  may  be  known, 


OF  THE  TRUNK. 


75 


viz.  thM  each  vertebra  bears  two  impressions  of  the  rib  w'hich 
was  joined  to  it,  one  on  the  flat  side  of  its  body,  and  the  other 
on  the  fore  part  of  its  transverse  process.  The  articulating 
processes  are  so  short,  that  they  can  hardly  be  described  as  dis- 
tinct projections,  as  they  stand  out  so  directly  from  the  trans- 
verse process,  appearing  as  parts  of  it. 

We  may  distinguish  the  first  vertebra  of  the  back,  by  its 
having  the  whole  of  the  head  of  the  rib  impressed  upon  its 
side. 

The  12th,  or  lowest  dorsal  vertebra,  has  also  the  entire  head 
of  the  rib  impressed  upon  it,  and  it  has  no  articulating  surface 
on  the  extremity  of  the  transverse  process. 

Of  the  vERTEBKiE  OF  THE  NECK. — The  Vertebra;  of  the  neck 
depart  still  farther  from  the  common  form.  Their  bodies  are 
flattened  on  their  fore  parts,  so  as  to  make  a flat  surface  on 
which  the  windpipe  and  gullet  lie  smooth.  The  body  is  very 
small  in  all  the  vertebrae  of  the  neck.  In  the  uppermost  of 
the  neck  there  is  absolutely  no  body  ; and  the  next  to  that  has 
not  a body  of  the  regular  and  common  form.  There  is  not  in 
the  vertebrae  of  the  neck,  as  in  those  of  the  loins,  a cup  or  hol- 
low for  receiving  the  intervertebral  substance,  but  the  surfaces 
of  the  body  are  flat  or  plain,  and  the  articulating  processes  are 
oblique,  and  make  as  it  were,  one  articulation  with  the  body ; 
for  the  lower  surface  of  the  body  being  not  hollow,  but  plain, 
and  inclined  forwards,  and  the  articulating  processes  being  also 
inclined  backwards,  the  two  surfaces  are  plain,  opposed  to  each 
other,  and  the  one  prevents  the  vertebrae  from  sliding  forwards, 
and  the  other  prevents  it  from  sliding  backwards,  while  a pretty 
free  and  general  motion  is  allowed.  The  spinous  processes 
of  the  neck  are  short  and  project  directly  backwards;  they  are 
ior  the  insertion  of  many  muscles,  and  therefore  they  are  split. 
This  bifurcation  of  the  spinous  process  is  not  absolutely  pe- 
culiar to  the  cervical  vertebras ; for  sometimes,  though  rarely, 
the  others  are  so  : and  it  is  only  in  the  middle  of  the  neck 
that  even  they  are  forked  ; for  the  first  vertebra  is  a plain  ring, 
with  hardly  any  spinous  process,  because  there  are  few  mus- 
cles attached  to  it ; and  the  process  hf  the  last  vertebra  of  the 
neck  is  not  bifurcated,  so  that  it  approaches  to  the  nature  of 
the  dorsal  vertebrae ; the  spinous  process  is  long  and  aquiline; 
is  depressed  towards  the  back,  and  is  so  much  longer  than  the 
others,  as  to  be  distinguished  by  the  name  of  vertebra 

promine  NS. 

The  TRANSVERSE  PROCESSES  of  the  neck  are  also  bifurcated, 
because  there  are  a great  many  small  muscles  inserted  into 
them  also.  But  the  most  curious  peculiarity  of  the  transverse 
processes  is  that  each  of  them  is  perforated  for  the  transmission 


76 


OF  THE  TRUNK. 


of  the  great  artery,  which  is  named  vektebral  artery,  because 
it  passes  through  these  holes  in  the  vertebrae,  which  form  alto- 
gether a bony  canal  for  the  artery.  This  artery,  which  is  de- 
fended with  so  much  care,  is  one  of  the  chief  arteries  of  the 
brain,  for  there  are  two  only ; and  often  when  the  other,  the 
carotid,  has  been  obstructed,  this  continues  to  perform  its 
office. 

So  that  the  character  of  these  cervical  vertebrie  is,  that  they 
are  calculated  for  much  free  motion  ; and  the  marks  by  which 
they  are  distinguished  are,  that  the  bodies  are  particularly 
small  ; the  aiticulating  processes  oblique,  with  regard  to  their 
position,  and  almost  plain  on  their  surface.  The  spinous  pro- 
cess, which  is  nearly  wanting  in  the  uppermost  vertebrse,  is 
short  and  forked  in  all  the  lower  ones  ; the  transverse  process 
also  is  forked  ; and  the  transverse  processes  of  all  the  verte- 
br<E,  except  sometimes  the  first  and  last,  are  perforated  near 
their  extremities  with  the  large  hole  of  the  vertebral  artery. 

ATLAS  AND  DENTATUS. — But  among  these  vertebrae 
of  the  neck,  two  are  to  be  particularly  distinguished,  as  of 
greater  importance  than  all  the  rest ; for  though  the  five  lower 
vertebrae  of  the  neck  be  ossified  and  fixed,  if  but  the  two  up- 
permost remain  free,  the  head,  and  even  the  neck,  seem  to 
move  with  perfect  ease. 

The  first  vertebra  is  named  atlas,  perhaps,  because  the 
globe  of  the  head  is  immediately  placed  upon  it ; the  second 
is  named  dentata  or  axis,  because  it  has  an  axis  or  tooth-like 
process  upon  which  the  first  turns. 

The  atlas  has  not  the  complete  form  of  the  other  vertebrae 
of  the  neck,  for  its  processes  are  scarcely  distinguishable  : it 
has  no  body,  unless  its  two  articulating  processes  are  to  be 
reckoned  as  a body  : it  is  no  more  than  a simple  ring  ; it  has 
hardly  any  spinous  process  ; and  its  transverse  process  is  long 
but  not  forked.  On  the  upper  margin  of  the  ring  may  be  ob- 
served the  mark  of  the  ligament  which  unites  it  to  the  margin 
of  the  occipital  bone  ; and  on  the  lower  margin  of  the  ring  the 
mark  of  attachment  of  a similar  ligament,  which  attaches  it  to 
t'  0.  c rcle  of  the  dentata.  The  boj)t  is  entii’cly  wanting ; in  its 
place,  the  vertebra  has  a flat  surface  looking  backwards,  which 
is  smooth  and  polishc  d by  the  rolling  of  the  tooth-like  process ; 
there  is  also  a sharp  point  rising  perpendicularly  upwards  to- 
wards the  occipital  bone,  and  this  point  is  held  to  the  edge  of 
the  occipital  hole  by  a strong  ligament.  The  smooth  mark 
of  the  tooth-like  process  is  easily  found  ; and  upon  either  side 
of  it,  there  projects  a small  point  from  the  inner  circle  of  the 
ring  : these  two  points  have  a ligament  extended  betwixt  them, 


OF  THE  TRUNK. 


11 


called  the  transverse  ligament,  which,  like  abridge,  divides  the 
ring  into  two  openings ; one  the  smaller,  for  lodging  the  tooth- 
like process,  embracing  it  closely  ; the  greater  opening  is  for 
the  spinal  marrow  : the  ligament  confines  the  tooth-like  pro- 
cess ; and  when  the  ligament  is  burst  by  violence  (as  has  hap- 
pened,) the  tooth-like  process,  broken  loose,  presses  upon  the 
spinal  marrow;  the  head,  ho  longer  supported  by  it,  falls  for- 
ward, and  the  patient  dies.  On  the  inside  and  lateral  part  of 
the  circle,  the  origin  of  the  lateral  ligaments  of  the  dentatus 
may  also  be  observed. 

The  articulating  process  may  be  considered  as  the  body 
of  this  vertebra  ; for  it  is  at  once  the  only  thick  part,  and  the 
only  articulating  surface.  This  broad  articulating  substance  is 
in  the  middle  of  each  side  of  the  ring  : it  lias  two  smooth  sur- 
faces on  each  side,  one  looking  upwards,  by  which  it  is  joined 
to  the  occiput ; and  one  looking  directly  downwards,  by  which 
it  is  joined  to  the  second  vertebra  of  the  neck.  The  two  up- 
per articulating  surfaces  are  oval,  and  slightly  hollow  to  receive 
the  occipital  condyles : they  are  also  oblique,  for  the  inner 
margin  of  each  dips  downwards  ; the  outer  margin  rises  up- 
wards ; and  the  fore  end  of  each  oval  is  turned  a little  towards 
its  fellow.  Now,  by  the  obliquity  of  the  condyles,  and  this 
obliquity  of  the  sockets  which  receive  them,  all  rotatory  mo- 
tion is  prevented,  and  the  head  performs,  by  its  articulations 
with  the  first  vertebra  or  atlas,  only  the  nodding  motions  ; and 
when  it  rolls,  it  carries  the  first  vertebra  along  with  it,  moving 
round  the  tooth-like  process  of  the  dentatus.  The  articula- 
tion with  the  head  is  a binge  joint,  in  the  strictest  sense  : it 
allows  ol  no  other  motion  than  that  backwards  and  forwards  ; 
the  nodding  motions  are  performed  by  the  head  upon  the  atlas, 
the  rotatory  motions  are  performed  by  the  atlas  moving  along 
with  the  head,  turning  upon  the  tooth-like  process  of  the  den- 
tatus. 

Now  the  upper  articulating  surface  of  the  atlas  is  hollowed 
to  secure  the  articulation  with  the  head ; but  the  lower  arti- 
culation, that,  with  the  dentatus,  being  secured  already  by  the 
tooth-like  process  of  that  bone,  no  other  properly  is  required 
in  the  lower  articulating  surface  of  the  atlas,  than  that  it  should 
glide  with  perfect  ease  ; for  which  purpose,  it  is  plain  and 
smooth  ; it  neither  receives,  nor  is  received  into  the  dentatus 
by  any  hollow,  but  lies  flat  upon  the  surface  of  that  bone.  It 
is  also  evident,  that  since  the  office  of  the  atlas  is  to  turn  along 
with  the  head,  it  could  not  be  fixed  to  the  dentatus,  in  the 
common  way,  by  a body  and  by  inteiwertebral  substance  ; and 
since  the  atlas  attached  to  the  head  move,',  along  with  it,  turn- 
ing as  upon  an  axis,  it  must  have  no  spinous  process  ; for 


78 


OF  THE  TRUNK. 


the  projection  of  a spinous  process  must  have  prevented  its 
turning  upon  the  dentatus,  and  would  even  have  hindered  in 
some  degree,  the  nodding  of  the  head  ; therefore  the  atlas  has 
a simple  ring  behind,  and  has  only  a small  knob  or  button 
where  the  spinous  process  should  be,  which,  however,  has  a 
small  notch  on  it.  The  transverse  process  is  not  forked, 
but  it  is  perforated  with  a large  hole  for  the  vertebral  artery  ; 
and  the  artery,  to  get  into  the  skull,  makes  a wide  turn,  lying 
flat  upon  the  bone,  by  which  there  is  a slight  hollow  or  impres- 
sion of  the  artery,  which  makes  the  ring  of  the  vertebra  ex- 
ceedingly thin. 

But  the  form  of  the  dentatus  best  explains  these  peculiarities 
of  the  atlas,  and  this  turning  of  the  head. 

The  DENTATA  or  AXIS  is  so  named  from  its  projecting 
point,  which  is  the  chief  characteristic  of  this  bone.  When  the 
dentata  is  placed  upright  before  us,  we  observe,  1.  That  it  is 
most  remarkably  conical,  rising  all  the  way  upwards,  by  a 
gradual  slope,  to  the  point  of  its  tooth-like  process.  2.  That 
the  ring  of  the  vertebra  is  very  deep,  that  is,  very  thick  in  its 
substance,  and  that  the  opening  of  the  ring  for  transmitting  the 
spinal  marrow  is  of  a triangular  form.  3.  That  its  spinous  pro- 
cess is  short,  thick,  and  forked ; and  that  it  is  turned  much 
dowawards,  so  as  not  to  interfere,  in  any  degree,  with  the  ro- 
tation of  the  atlas.  4.  That  its  tooth-like  process,  from  which 
the  bone  is  named,  is  very  large,  about  half  an  inch  in  length  ; 
very  thick,  like  the  little  finger  ; that  it  is  pointed  ; and  that 
from  this  rough  point  a strong  ligament  goes  upwards,  by  which 
the  tooth  is  tied  to  the  great  hole  of  the  occipital  bone.  We 
also  observe  a neck  or  collar,  or  smaller  part,  near  the  root  of 
the  tooth-like  process,  where  it  is  grasped  by  the  ring  of  the 
atlas;  while  the  point  swells  out  a little  above  ; so  that  with- 
out the  help  of  ligaments,  it  is  almost  locked  in  its  place.  We 
find  this  neck  particularly  smooth  ; for  it  is  indeed  upon  this 
collar  that  the  head  continually  turns.  And,  we  see  on  either 
side  of  this  tooth-like  process  abroad  and  flat  articulating  sur- 
face, one  on  either  side.  These  articulating  surfaces  are  pla- 
ced like  shoulders ; and  the  atlas  being  threaded  by  the  tooth- 
like process  of  the  dentatus,  is  set  flat  down  upon  the  high 
shoulders  of  this  bone,  and  there  it  turns  and  performs  all  the 
rotatory  motions  of  the  head. 

On  the  side  of  the  tooth-like  process  we  may  observe  the 
insertion  of  the  lateral  ligaments,  and  its  point  is  grasped  by 
the  perpendicular  ligament. 

We  may  observe,  that  the  superior  articulating  process  is 


OF  THE  TRUNK. 


79 


horizontal.  The  lower  surface  of  this  vertebra  resembles  the 
other  inferior  vertebra  of  the  neck. 

Of  the  medullary  tube,  and  the  passage  of  the 
NERVES. — All  the  vertebrse  conjoined  make  a large  canal  of  a 
triangular  or  roundish  form,  in  which  the  spinal  marrow  lies, 
giving  off  and  distributing  its  nerves  to  the  neck,  arms,  and 
legs ; and  the  whole  course  of  the  canal  is  rendered  safe  for 
the  marrow,  and  very  smooth  by  lining  membranes,  the  outer- 
most of  which  is  of  a leather-like  strength  and  thickness,  and 
serves  this  double  purpose  ; that  it  is  at  once  a hollow  liga- 
ment to  the  whole  length  of  the  spine  upon  which  the  bones 
are  threaded,  and  by  which  each  individual  bone  is  tied  and 
fixed  to  the  next ; and  it  is  also  a vagina  or  sheath  which  con- 
tains the  spinal  marrow,  and  which  is  bedewed  on  its  internal 
surface  with  a thin  exudation,  keeping  the  sheath  moist  and 
soft,  and  making  the  enclosed  marrow  lie  easy  and  safe. 

All  down  the  spine,  this  spinal  medulla  is  giving  off  its 
nerves  : One  nerve  passes  from  it  at  the  interstice  of  each  ver- 
tebra ; so  that  there  are  twenty-four  nerves  of  the  spine,  or 
rather  forty-eight  nerves  ; twenty-four  being  given  towards  each 
side  ; these  nerves  pass  each  through  an  opening  or  small  hole 
in  the  general  sheath ; there  they  pass  through  the  interstice 
of  each  vertebra ; so  that  there  is  no  hole  in  the  bone  requir- 
ed, but  the  nerve  escapes  by  going  under  tbe  articulating  pro- 
cess. This,  indeed,  is  converted  into  something  like  a hole, 
when  the  two  contiguous  vertebrae  are  joined  to  each  other. 

THE  INTERVERTEBRAL  SUBSTANCE— The  in- 
tervertebral substance  is  that  which  is  interposed  betwixt  the 
bodies  of  two  adjoining  vertebrae,  and  which  is  (at  least  in  the 
loins)  nearly  equal  in  thickness  to  the  back  of  the  body  of  the 
vertebra  to  which  it  belongs.  We  give  it  this  undefined  name, 
because  there  is  nothing  in  the  human  system  to  which  it  is 
entirely  similar ; for  it  is  not  ligament,  nor  is  it  cai’tilage,  but  it 
is  commonly  defined  to  be  something  of  an  intermediate  nature  : 
It  is  a soft  and  pliant  substance,  which  is  curiously  folded  and 
returned  upon  itself,  like  a rolled  bandage  with  folds,  gradual- 
ly softer  towards  the  centre,  and  with  the  rolled  edges  as  if  cut 
obliquely  into  a sort  of  convex.  The  cut  edges  are  thus  turn- 
ed towards  the  surface  of  the  vertebra,  to  which  each  interver- 
tebral substance  belongs : it  adheres  to  the  face  of  each  ver- 
tebra, and  it  is  confined  by  a strong  ligament  all  round  : and 
this  substance,  though  it  still  keeps  its  hold  on  each  of  the  two 
vertebrae  to  which  it  belongs,  though  it  permits  no  true  motion 
of  one  bone  on  another,  but  only  by  twisting  of  its  substance, 
yields,  nevertheless,  easily  to  whichever  side  we  incline,  and  it 


80 


OF  THE  TRUNK. 


returns  in  a moment  to  its  place  by  a very  powerful  resilience. 
This  perfect  elasticity  is  the  chief  character  and  virtue  of  this 
intervertebral  substance,  whose  properties  indeed  are  best  ex- 
plained by  its  uses;  for,  in  the  bendings  of  the  body,  it  yields 
in  a very  considerable  degree,  and  rises  on  the  moment  that 
the  weight  or  the  force  of  the  muscles  is  removed.  In  leaping, 
in  shocks,  or  in  falls,  its  elasticity  prevents  any  harm  to  the 
spine,  while  other  less  important  joints  are  luxated  and  destroy- 
ed. During  the  day.  it  is  continually  yielding  under  pressure ; 
so  that  we  are  an  inch  taller  in  the  morning  than  at  night;  we 
are  shorter  in  old  age  than  in  youth  ; and  the  aged  spine  is 
bended  forwards  by  the  yielding  of  this  part.  These  curious 
facts  were  first  observed  by  a sort  of  chance,  and  have  since 
been  ascertained  with  particular  care. 

Since  pressure,  in  length  of  years,  shortens  the  forepart  of 
the  column  of  the  spine,  and  makes  the  body  stoop,  any  un- 
due inclination  to  either  side  will  cause  distortion : the  sub- 
stance yields  on  one  side,  and  rises  on  the  other;  and  at  last 
the  same  change  happens  in  the  bones  also,  and  the  distortion 
is  fixed,  and  not  to  be  changed  : this  is  peculiarly  apt  to  hap- 
pen with  children  whose  bones  are  growing,  and  whose  gristles 
and  intervertebral  substances  are  peculiarly  soft;  so  that  a 
tumour  on  the  head  or  jaw,  which  makes  a boy  carry  his  head 
on  one  side,  or  constant  stooping,  such  as  is  used  by  a girl  in 
working  at  the  tambour,  or  the  carrying  of  a weakly  child  al- 
ways on  one  arm  by  a negligent  or  awkward  nurse,  will  cause 
in  time  a fixed  incurable  distortion. 

We  are  now  qualified  to  understand  the  motions  of  the  ver- 
tebrae, and  to  trace  the  degree  of  motion  in  each  individual 
class.  The  degrees  of  motion  vary  with  the  forms  of  the  ver- 
tebra;, in  each  part  of  the  spine  : the  motion  is  freest  in  the 
neck,  more  limited  in  the  loins,  and  in  the  back  (the  middle 
part  of  the  spine)  scarcely  any  motion  is  allowed  : the  head 
performes  all  the  nodding  motions  upon  the  first  vertebra  of 
the  neck  : the  first  vertebra  of  the  neck  performs  again  all  the 
quick  and  short  turnings  of  the  head,  by  moving  upon  the  den- 
tatus : all  the  lower  vertebra;  of  the  neck  are  also  tolerably 
free,  and  favour  these  motions  by  a degree  of  turning ; and  all 
the  bendings  of  the  neck  are  performed  by  them.  The  dor- 
sal vertebrae  are  the  most  limited  in  their  movements,  bending 
chiefly  forwards  by  the  yielding  of  their  intervertebral  sub- 
stance. The  vertebrae  of  the  loins  again  move  largely,  for 
their  intervertebral  substance  is  deep,  and  their  processes  quite 
unentangled  and  free.  To  perform  these  motions,  each  ver- 
tebra has  two  distinct  joints,  as  different  in  office  as  in  form  : 
first,  each  vertebra  is  fixed' to  those  above  and  below  by  the 


©F  THE  TRUNK. 


81 


intervertebral  substance,  which  adheres  so  to  each,  that  there 
is  no  true  motion  : there  is  no  turning  of  any  one  vertebra  up- 
on the  next ; but  the  elasticity  of  the  intervertebral  substance 
allows  the  bones  to  move  a little,  so  that  there  is  a general 
twisting  and  gentle  bending  of  the  whole  spine.  The  second 
joint  is  of  the  common  nature  with  the  other  joints  of  the 
body,  for  the  articulating  processes  are  faced  with  cartilage, 
surrounded  with  a capsule,  and  lubricated  with  a mucus.  And 
I conceive  this  to  be  the  intention  of  the  articulating  processes 
being  produced  to  such  a length,  that  they  may  lap  over  each 
other  to  prevent  luxations  of  the  spine ; and  they  must,  of 
course,  have  these  small  joints,  that  they  may  yield  to  this 
general  bending  of  the  spine. 

RIBS  AND  STERNUM. 

Of  the  kibs. — The  ribs,  whose  office  it  is  to  give  form  to 
the  thorax,  and  to  cover  and  defend  the  lungs,  also  assist  in 
breathing  : for  they  are  joined  to  the  vertebra  by  regular 
hinges,  which  allow  of  short  motions,  and  to  the  sternum  by 
cartilages,  which  yield  to  the  motion  of  the  ribs,  and  return 
again  when  the  muscles  cease  to  act. 

Each  rib,  then,  is  characterised  by  these  material  parts ; a 
great  length  of  bone,  at  one  end  of  which  there  is  a head  for 
articulation  with  the  vertebrae,  and  a shoulder  or  knob  for  arti- 
culation with  its  transverse  process ; at  the  other  end  there  is  a 
point,  with  a socket  for  receiving  its  cartilage,  and  a cartilage 
joined  to  it,  which  is  implanted  into  a similar  socket  in  the 
side  of  the  sternum,  so  as  to  complete  the  form  of  the  chest. 

The  ribs  are  twelve  in  number,  according  to  the  number  of 
the  vertebrae  in  the  back,  of  which  seven  are  named  true  ribs, 
because  their  cartilages  join  directly  with  the  sternum  ; and 
five  are  named  false  ribs,  because  their  cartilages  are  not  sepa- 
rately nor  directly  implanted  into  the  sternum,  but  are  joined 
one  with  another;  the  cartilage  of  the  lower  rib  being  joined 
and  lost  in  that  of  the  rib  above,  so  that  all  the  lower  ribs  run 
into  one  greater  cartilage.  But  there  is  still  another  distinction, 
viz.  that  the  last  rib,  and  commonly  also  the  rib  above,  are  not 
at  all  implanted  in  the  sternum,  but  are  loosely  connected  only 
with  the  muscles  of  the  abdomen,  whence  they  are  named  the 
loose  or  floating  ribs. 

The  ribs  are,  in  general,  of  a flattened  form,  their  flat  sides 
being  turned  smooth  towardsthe  lungs.  But  this  flatness  of  the 
fib  is  not  regular,  it  is  contorted,  as  if  the  soft  rib  had  been 
seized  by  either  end,  and  twisted  betwixt  the  hands  : the  mean- 
ing of  which  is,  to  accommodate  the  flatness  of  the  rib  to  the 

VOL.  r.  L 


82 


OF  THE  TRUINK. 


form  which  the  thorax  assumes  in  all  its  degrees  of  elevation  ; 
for  when  the  I'ib  rises,  and  during  its  rising  through  all  the  de- 
grees of  elevation,  it  still  keeps  its  Hat  side  towards  the 
lungs.  Though  of  a flattened  form,  the  rib  is  a little  rounded 
at  its  upper  edge,  is  sharp  and  cutting  at  its  lower  edge ; 
and  its  lower  edge  seems  double  ; for  there  is  a groove 
made  there  by  the  intercostal  artery  and  nerve.  They 
are  named  intercostal,  from  lying  betwixt  the  ribs,  the  artery 
being  rather  within  the  rib,  is  defended  in  some  degree  by  its 
groove,  the  lip  of  which  forms  the  lower  edge  of  the  rib,  but 
still  this  artery  is  not  without  reach  of  the  knife,  in  some  sur- 
gical operations  ; we  are  careful,  therefore,  to  mark,  that  it  runs 
on  the  lower  edge  of  the  rib,  and  is  of  the  size  of  a crow-quill  j 
and  that,  if  it  be  wounded,  it  will  bleed  largely  from  its  near- 
ness to  the  greatest  artery  of  the  body;  that  it  is  easily  shun- 
ned, by  keeping  the  knife  nearer  to  the  rib  below. 

On  each  rib  we  find  the  following  parts  : 1.  The  head,  or 
round  knob  by  which  it  is  joined  to  the  spine.  The  head  of 
each  rib  has  indeed  but  a small  articulating  surface  ; but  that 
smooth  surface  is  double,  or  looks  two  ways.  For  the  head  of 
the  rib  is  not  implanted  into  the  side  of  one  vertebra,  it  is 
rather  implanted  into  the  interstice  betwixt  two  vertebrae,  the 
head  touches  both  vertebra  ; all  the  vertebra  except  the  first 
and  last  bear  the  mark  of  two  ribs,  one  above,  and  one  below. 
The  mark  of  the  rib  is  on  the  edge  of  either  vertebra,  and  the 
socket  may  be  said  to  lie  in  the  intervertebral  substance  be- 
twixt them. 

2.  The  NECK  of  the  rib  is  a smaller  part,  immediately  before 
the  head.  Here  the  rib  is  particularly  small  and  round. 

3.  About  an  inch  from  the  head,  there  is  a second  rising,, 
or  bump,  the  articulating  surface  by  which  it  touches  and 
turns  upon  the  transverse  process  of  the  vertebra  below. 
These  two  articulations  have  each  a distinct  capsule  or  bag, 
each  is  a very  regular  joint,  and  the  degree  of  motions  of  the 
rib,  and  direction  in  which  it  moves,  may  be  easily  calcula- 
ted, from  the  manner  in  which  it  is  jointed  with  the  spine  ; for 
the  two  articulating  surfaces  of  the  rib  are  on  its  back  part; 
the  back  of  the  rib  is  simply  laid  upon  the  side  of  the  spine  ; 
the  joints  with  the  body  of  the  vertebrae,  and  with  its  trans- 
verse process,  are  in  one  line,  and  form  as  if  but  one  joint,  so 
that  the  rib  being  fixed  obliquely,  and  at  one  end  only,  that 
end  continues  firm,  except  in  turning  upon  its  axis ; the  two 
heads  roll  upon  the  body  of  the  vertebrae,  and  upon  the  trans- 
verse process ; and  so  its  upper  end  continues  fixed,  while  its  ^ 
lower  end  rises  or  falls ; and  as  the  motion  is  in  a circle,  the 


OF  THE  TRUNK.  88 

head  being  the  central  point,  moves  but  little,  while  the  lower 
end  of  the  rib  has  the  widest  range. 

4.  Just  above  the  second  articulating  surface  there  is  a se- 
cond tubei’cle,  which  has  nothing  to  do  with  the  joints,  but  is 
intended  merely  for  the  attachment  of  the  ligaments  and  mus- 
cles from  the  spine,  which  suspend  and  move  the  rib. 

5,  The  angle  of  the  rib  is  often  mentioned,  being  a common 
mark  for  the  place  of  surgical  operations.  There  is  a flatness 
of  the  thorax  behind,  forming  the  breadth  of  the  back ; the 
sharpness  where  this  flatness  begins  to  turn  into  the  roundness 
of  the  chest  is  formed  by  the  angles  of  the  ribs.  Each  rib  is 
round  in  the  place  of  its  head,  neck,  and  tubercles  ; it  grows 
flatter  a little,  as  it  approaches  the  angle  ; but  it  is  not  com- 
pletely flattened  till  it  has  turned  the  angle  which  is  the  proper 
boundary  betwixt  the  round  and  the  flat  parts  of  the  rib. 
This  anatomy  of  the  ribs  is  sufficiently  simple,  but  it  is  not 
equally  easy  to  observe  how  it  bears  on  the  practice  of  surgery. 
It  is  in  some  degree  useful  in  the  more  advanced  parts  of 
anatomy,  to  remember  the  names,  and  it  is  necessary,  even  in 
speaking  the  common  language  of  surgeons,  to  know  these 
parts,  viz.  the  head  of  the  rib  ; the  tubercle,  or  second  articu- 
lating surface  ; the  angle,  or  turning  forward  of  the  rib  ; the 
upper  round,  and  the  lower  flat  edge;  and  especially  to  re- 
member the  place  and  the  dangers  of  the  intercostal  artery. 
It  is,  however,  more  important  to  consider  the  connections  of 
parts,  as  the  seat  of  the  artery,  the  manner  in  which  the  ribs 
are  lined  with  the  pleura,  and  their  nearness  to  the  surface  of 
the  lungs.  There  are  some  peculiarities  in  individual  x'ibs, 
the  chief  of  which  are  these  : the  size  or  length  of  the  ribs 
gradually  decreases  from  the  first  to  the  last,  the  first  being 
exceedingly  short  and  circular,  the  lower  ones  longer,  and  al- 
most right  lined  ; so  that  the  thorax  is  altogether  of  a conical 
shape,  the  upper  opening  so  small  as  just  to  permit  the  trachea, 
oesophagus,  and  great  vessels  to  pass ; the  lower  opening  so 
large,  that  it  equals  the  diameter  of  the  abdomen  : the  first  rib 
is  consequently  very  short ; it  is  thick,  strong,  and  of  a flat- 
tened form  ; of  which  flatness  one  face  looks  upwards,  and 
another  downwards,  and  the  great  axillary  artery  and  vein  lie 
upon  its  flat  upper  surface.  We  do  not  see  any  groove  on  the 
lower  surface  for  the  intercostal  artery.  It  is  also  particularly 
circular,  making  more  than  half  a circle  from  its  head  to  the 
extremity  where  it  joins  the  stei’iium  ; it  has,  of  course,  no  an- 
gle, and  wants  the  distorted  twisting  of  the  other  ribs:  the 
second  rib  is  also  round,  like  the  first  rib.  The  eleventh  and 
twelfth,  or  the  floating  ribs,  are  exceedingly  small  and  delicate, 
and  their  cartilage  terminates  in  an  acute  point,  unconnected 


84 


OF  THE 


with  the  sternum  ; and  lastly,  the  heads  of  the  first,  and  of  the 
twelfth  ribs,  are  rounder  than  any  of  the  others  ; for  these 
two  have  their  heads  implanted  into  the  flat  side  of  one  verte- 
bra only,  while  all  the  others  have  theirs  implanted  hetwixt  the 
bodies  of  two  vertebrae.  And  there  is  this  further  difference, 
that  in  the  eleventh  and  twelfth  ribs  there  are  no  tubercles  for 
the  articulation  with  the  transverse  processes. 

The  cartilages  of  the  ribs  complete  the  form  of  the  thorax, 
and  form  all  the  lunated  edge  of  that  cavity ; and  it  is  from 
this  cartilaginous  circle  that  the  great  muscle  of  the  diaphragm 
has  its  chief  origin,  forming  the  partition  betwixt  the  thorax 
and  the  abdomen.  The  farther  end  of  each  rib  swells  out 
thick  and  spongy,  and  has  a small  socket  for  lodging  the  carti- 
lage ; for  these  cartilages  are  not  joined  like  the  intervertebral 
substances  with  their  bones  : but  there  is  a sort  of  joint  very 
little  moveable  indeed,  but  still  having  a rude  socket,  and  a 
strong  capsular  ligament,  and  capable  of  luxation  by  falls  and 
blows;  the  implantations  into  the  sternum  are  evidently  by 
fair  round  sockets,  which  are  easily  distinguished  upon  the 
two  edges  of  that  bone.  These  cartilages  may  be  enumerated 
thus.  The  cartilages  of  the  first  and  second  ribs  descend  to 
touch  the  sternum.  The  cartilage  of  the  third  rib  is  direct. 
The  cartilages  of  the  fourth,  fifth,  and  sixth  ribs  rise  upwards, 
in  proportion  to  their  distance  from  this  central  one.  The  first 
five  ribs  have  independent  cartilages ; the  eighth,  ninth,  and 
tenth  ribs  run  their  cartilages  into  the  cartilage  of  the  seventh 
rib  ; and  the  eleventh  and  twelfth  ribs  have  their  cartilages 
small,  unconnected,  and  floating  loose. 

By  the  motion  of  the  ribs,  the  thorax  is  alternately  dilated 
and  diminished  in  capacity,  the  lungs  thereby  having  tiieir 
play.  A rib  has  two  motions.  1 . Its  sternal  end  rises  and 
falls,  the  centre  of  motion  being  in  the  articulation  with  the 
spine.  2.  It  moves  on  its  own  axis ; a line  drawn  through  the 
two  extremities  is  the  centre  of  this  motion.  The  former  mo- 
tion enlarges  and  diminishes  the  diameter  of  the  thorax,  from 
the  spine  to  the  sternum,  this  enlarges  the  lateral  diameter  of 
the  thorax. 

The  Sternum. — ^The  sternum  is  that  long  and  squared 
bone,  which  lies  on  the  forepart  of  the  breast  over  the  heart, 
and  which  being  joined  by  the  cartilages  of  the  ribs, 
completes  the  cavity  of  the  chest;  it  is  for  corapleiing  the 
thorax,  and  defending  the  heart,  for  a medium  of  attachment 
to  the  ribs,  and  for  a fulcrum  or  point,  on  which  the  clavicles 
may  roll. 

This  bone  is  light  and  spongy,  and  has  a thin  outer  cortex, 
but  depends  in  a great  measure  on  the  attachment  of  liga- 


OF  THE  TRUNK.  85 

ments  and  tendons  for  its  strength.  From  its  structure  it  is 
liable  to  scrofulous  disease. 

We  find  the  sternum  consisting  in  the  child  of  eight  distinct 
pieces,  which  run  together  in  the  progress  of  life,  and  which 
in  old  age,  are  firmly  united  into  one ; but  in  all  the  middle 
stage  of  lile,  we  find  three  pieces  in  the  sternum,  two  of  which 
are  properly  bone,  the  third  remains  a cartilage  till  very  late 
in  life,  and  is  named  the  ensiform  cartilage,  from  its  sword- 
like point. 

It  is  found  to  have  eight  pieces,  even  in  the  child  of  six 
years  old  ; some  years  after,  it  has  but  five  or  six ; and  the  sa- 
lient white  lines  which  traverse  the  bone,  mark  where  the  in- 
termediate cartilages  have  once  been. 

1 . The  upper  piece  of  the  sternum  is  very  large,  roundish 
or  rather  triangular,  resembling  the  form  of  the  heart  on  play- 
ing-cards : it  is  about  two  inches  in  length,  and  an  inch  and  a 
half  in  breadth ; and  these  marks  are  easily  observed.  The 
APEX,  or  point  of  the  triangle,  is  pointed  downwards  to  meet 
the  second  bone  of  the  sternum.  The  base  of  the  tri- 
angle, which  is  uppermost,  towards  the  root  of  thd  throat 
seems  a little  hollowed,  for  the  trachea  passing  behind  it.  On 
each  upper  corner,  it  has  a large  articulating  hollow,  into  which 
the  ends  of  the  collar  bones  are  received  ; (for  this  bone  is  the 
steady  fulcrum  upon  which  they  roll.)  A little  lower  than 
this,  and  upon  its  side  is  the  socket  for  receiving  the  short  car- 
tilage of  the  first  rib ; and  the  second  rib  is  implanted  in  the 
interstice  betwixt  the  first  and  second  bone  of  the  sternum  ; 
so  that  one  half  of  the  socket  for  its  cartilage  is  found  in  the 
lower  part  of  this  bone,  and  the  other  half  in  the  upper  end  of 
the  next. 

2.  The  second  piece  of  the  sternum,  is  of  a squared  form, 
very  long  and  flat,  and  composing  the  chief  length  of  the  ster- 
num ; for  the  first  piece  receives  only  the  cartilage  of  the 
first  rib,  and  one  half  of  the  second ; but  this  long  piece  re- 
ceives, on  each  side  or  edge  of  it,  the  cartilages  of  eight  ribs: 
but  as  three  of  the  lower  cartilages  are  run  into  one,  there  are 
but  five  sockets  or  marks.  The  sockets  for  receiving  the  car- 
tilages of  the  ribs,  are  on  the  edges  of  the  sternum  ; they  are 
very  deep  in  the  firm  substance  of  the  bone,  and  large  enough 
to  r'eceive  the  point  of  the  finger  with  ease : and  whoever  com- 
pares the  size  and  deepness  of  these  sockets,  with  the  round 
heads  of  the  cartilages  which  enter  into  them,  will  no  more 
doubt  of  distinct  joints  here,  than  of  the  distinct  articulation  of 
the  vertebras  with  each  other. 

3.  This  is,  in  truth,  the  whole  of  the  bony  sternum ; and 
what  is  reckoned  the  third  piece,  is  a cartilage  merely,  and 


86 


QF  THE  TRONK. 


continues  so  down  to  extreme  old  age.  This  cartilage  which 
ekes  out,  and  lengthens  the  sternum,  and  which  is  pointed  like 
a sword,  is  thence  named  cartilago  mucronata,  the  pointed 
cartilage,  or  cartilago  ensjformis,  or  xiphoides,  the  sword- 
like  cartilage.  One  half  of  the  pit  for  the  attachment  of  the 
seventh  rib  is  on  this  portion.  This  cartilaginous  point  extend- 
ing downwards  over  the  belly,  gives  a sure  origin  and  greater 
power  to  the  muscles  of  the  abdomen,  and  that  without  embar- 
rassing the  motions  of  the  body ; but  this  cartilage,  which  is 
commonly  short  and  single  pointed,  is  sometimes  forked, 
sometimes  bent  inwards,  so  (it  has  been  thought)  as  to  occa- 
sion sickness  and  pain ; and  once  was  produced  to  such  a 
length,  as  to  reach  the  navel,  and  ossified  at  the  same  time, 
so  as  to  hinder  the  bending  of  the  body,  and  occasion  much 
distress. 

The  sternum  and  the  ribs,  and  all  the  chest  stand  so  much 
exposed,  that  did  we  not  naturally  guard  them  with  the  hands, 
fractures  must  be  very  frequent,  but  indeed  when  they  are 
broken,  and  beaten  in,  they  hurt  the  heart  or  lungs,  and  not  un- 
frequently  the  most  dreadful  consequences  ensue.  I have  al- 
ready explained  that  this  class  of  bones,  defending  the  most 
noble  viscera  (next  to  the  brain,)  the  injuries  are  almost  as 
fatal  as  injuries  of  the  brain ; often  by  a wheel  passing  over 
the  body,  the  sternum  is  broken,  its  pieces  press  inwards  upon 
the  heart,  which  is  sometimes  burst ; but  more  commonly  the 
patients  die  a slow  and  miserable  death  ; for  the  inflammation, 
which  begins  in  the  place  of  the  w'ound  is  extended  to  the 
lungs,  is  propagated  still  onwards  to  the  heart,  and  the  heart 
being  once  inflamed,  there  comes  anxiety,  oppression,  faint- 
ings  and  palpitations;  anxious  breathing,  quick  and  interrupt- 
ed pulse  ; still  more  frequent  faintings,  and  then  death.  The 
ribs  cover  more  properly  the  lungs,  where  the  wound  or  in- 
flammation is  not  always  fatal ; for  the  wound  by  the  point  of 
the  rib,  is  no  deeper  than  just  to  puncture  the  lungs ; but 
through  this  small  wound  on  their  surface,  the  lungs  breathe 
out  their  air  into  the  cavity  of  the  chest,  and  at  last  it  escapes 
under  the  cellular  substance  of  skin  ; the  man  is  blown  up  to  a 
prodigious  degree  with  continually  increasing  anxiety,  the 
breathing  more  and  more  interrupted,  and  were  he  not  assisted, 
he  would  die. 


PELVIS. 

To  give  a steady  bearing  to  the  trunk,  and  to  connect  it 
with  the  lower  extremities  by  a sure  and  firm  joining,  the  pel- 


OF  THE  TRUNK. 


87 


vis  is  interposed,  which  is  a circle  of  large  and  firm  bones, 
standing  as  an  arch  betwixt  the  lower  extremities  and  the 
trunk.  Its  arch  is  wide  and  strong,  so  as  to  give  a firm  bear- 
ing to  the  body ; its  individual  bones  are  large,  so  as  to  give  a 
deep  and  sure  socket  for  the  implantation  of  the  thigh-bone ; 
its  motions  are  free  and  large,  bearing  the  trunk  above  and 
rolling  upon  the  thigh  bones  below ; and  it  is  so  truly  the 
centre  of  all  the  great  motions  of  the  body,  that  when  we  be- 
lieve the  motion  to  be  in  the  higher  parts  of  the  spine,  it  is 
either  the  last  vertebra  of  the  loins  bending  upon  the  top  of 
the  pelvis,  or  the  pelvis  itself  rolling  upon  the  head  of  the 
thigh  bones. 

The  PELVIS  is  named  partly,  perhaps,  from  its  resembling 
a basin  in  its  form ; or  perhaps,  from  its  office  of  containing 
the  urinary  bladder,  rectum,  vagina,  and  womb;  it  consists 
in  the  child  of  many  pieces,  but  in  the  adult  it  is  formed  of 
four  large  bones,  of  the  os  sacrum  behind  the  ossa  innominata 
on  either  side,  and  the  os  coccygis  below. 

Os  SACRUM. — The  names  os  sacrum,  os  basillare,  &c.  seem 
to  relate  rather  to  its  greater  size  than  to  its  ever  having  been 
offered  in  sacrifice.  This  bone,  with  its  appendix  the  os  coc- 
cygis, is  called  the  false  spine,  or  the  column  of  the  false  ver- 
tebrse ; authors  making  this  distinction,  that  the  true  vertebrae 
are  those  of  the  back,  neck,  and  loins,  a column  which  grows 
gradually  smaller  upwards ; the  false  vertebrae  are  those  of  the 
sacrum  and  coccyx,  which  are  conical,  with  the  apex  or  point 
downwards,  and  the  base,  viz.  the  top  of  the  sacrum,  turned 
upwards  to  meet  the  true  spine. 

The  bones  of  which  the  sacrum  is  composed,  had  driginally 
the  form  of  distinct  small  vertebrae.  These  distinctions  are 
lost  in  the  adult,  or  are  recollected  only  by  the  marks  of  former 
lines,  for  the  original  vertebrae  are  now  united  into  one  large 
and  firm  bone,  which  is  named  the  column  of  false  vertebrae ; 
because,  having  no  motion,  it  wants  the  chief  character  and 
use  of  the  true  ones. 

We  can  recognize  the  original  vertebrae,  even  in  the  adult 
bone,  for  we  find  it  regularly  perforated  with  holes,  for  the 
transmission  of  the  spinal  nerves ; we  find  these  holes  regular- 
ly disposed  in  pairs ; we  see  a distinct  white  and  rising  line 
which  crosses  the  bone,  in  the  interstice  of  each  of  the  ori- 
ginal vertebrae,  and  marks  the  place  where  the  cartilage  once 
was  ; and  by  these  lines  being  five  in  number,  with  generally 
five  pairs  of  holes,  we  know  this  bone  to  have  consisted  once 
of  five  pieces,  which  are  now  joined  into  one.  The  remains 
of  former  processes  can  also  be  distinguished,  and  the  back  of 
the  bone  is  rough  and  irregular  from  the  old  spines. 


«F  THE  TRENK. 


•as 

The  os  sacrum,  thus  composed,  is  among  the  lightest  bones 
of  the  human  body,  with  the  most  spongy  substance,  the  thin- 
est  tables,  the  most  easily  broken,  and  its  injuries  of  the  most 
formidable  nature ; but  then  it  is  a bone  the  best  cemented, 
and  confirmed  by  strong  ligaments,  and  the  best  covered  by 
thick  and  cushion-like  muscles.  The  os  sacrum  is  of  a trian- 
gular shape  : the  base  of  the  triangle  turned  upwards  to  re- 
ceive the  spine  ; its  inner  surface  is  smooth,  to  permit  the  head 
of  the  child  in  labour  to  glide  easily  along,  and  its  outer  sur- 
face is  irregular  and  rough,  with  the  spines  of  former  vertebrae, 
giving  rise  to  the  great  glutaei  muscles,  (which  form  the  con- 
tour of  the  hip,)  and  to  all  the  strongest  muscles  of  the  back 
and  loins. 

It  has  in  it  a triangular  cavity  under  the  arch  of  its  spinous 
processes;  which  cavity  is  continued  from  the  canal  in  the  ver- 
tebrae of  the  spine ; and  this  cavity  of  the  sacrum  contains  the 
continuation  and  the  end  of  the  spinal  marrow,  which  being 
in  this  place  divided  into  a great  many  thread-like  nerves,  has 
altogether  the  form  of  a horse’s  tail,  and  is  therefore  named 
cauda  equina. 

From  this  triangular  cavity,  the  nerves  of  the  cauda  equina 
go  out  by  the  five  great  holes  on  the  forepart  of  the  sacrum, 
holes  large  enough  to  receive  the  point  of  the  finger:  the  first 
three  nerves  of  the  sacrum,  joining  with  the  last  two  nerves  of 
the  loins,  form  the  sacro-sciatic  nerve,  the  largest  in  the  body, 
which  goes  downward  to  the  leg,  while  the  two  lower  nerves 
of  the  sacrum  supply  the  contents  of  the  pelvis  alone. 

The  back  of  the  sacrum  is  also  perforated  with  holes,  whose 
size  is  nearly  equal  to  those  on  its  fore  part,  but  whose  use* 
are  not  so  distinctly  known ; for  the  small  nerves  which  pass 
outwards  by  them  to  the  muscles  of  the  loins  or  hips,  are  in 
no  degree  proportioned  to  the  size  of  the  holes. 

All  the  edges  of  this  triangle  form  articulating'  points,  by 
which  it  is  joined  to  other  bones.  The  base,  or  upper  part  of 
the  sacrum,  receives  the  last  vertebra  of  the  loins  on  a large 
broad  surface,  which  makes  a very  moveable  joint;  and  indeed, 
the  joining  of  the  last  true  vertebra,  with  the  top  of  the  sacrum, 
is  a point  where  there  is  more  motion  than  in  the  higher  parts 
of  the  spine.  The  sacrum  has  two  articulating  surfaces  which, 
stand  perpendicular,  and  correspond  with  those  of  the  lower 
lumbar  vertebra.  The  apex,  or  point  of  the  sacrum,  has  the 
os  coccygis  joined  to  it ; which  joining  is  moveable  till  the  age 
of  twenty  in  men,  and  till  the  age  of  forty-five  in  women  ; and 
the  meaning  of  its  continuing  longer  moveable  in  women,  i.s 
very  plain,  since  we  distinctly  feel  the  lower  point  of  the  coc- 
cyx in  women  yielding  in  the  time  of  labour,  so  as  to  enlarge 


OP  THE  TRUNK. 


89 


greatly  the  lower  opening  of  the  pelvis.  The  sides  of  the  os 
saprum  form  a broad,  rough,  and  deeply  indented  surface, 
which  receives  the  like  rough  surface  of  the  haunch  bones;  and 
here  the  surfaces  are  so  rough,  and  the  cartilage  so  thin,  that 
it  resembles  more  nearly  a suture ; and  by  the  help  of  the 
strong  ligaments,  and  of  the  large  muscles  which  arise  in  com- 
mon from  either  bone,  makes  a joining  absolutely  im- 
moveable, except  by  such  violent  force  as  is  in  the  end  fatal. 

Thus  the  original  state  of  this  bone  is  easily  recognised  and 
traced  by  many  marks ; it  stands  in  a conspicuous  place  of  the 
pelvis,  and  its  chief  office  is  to  support  the  trunk,  to  which  we 
may  add,  that  it  defends  the  cauda  equina,  transmits  its  great 
nerves,  forms  chiefly  the  cavity  of  the  pelvis  ; and  that  it  is 
along  the  hollow  of  this  bone  that  the  accoucheur  calculates 
the  progress  of  the  child’s  head  in  labour. 

The  os  coccYGis,  so  named  from  its  resemblance  to  the 
beak  of  a cuckow,  is  a small  appendage  to  the  point  of  the 
sacrum,  terminating  this  inverted  column  with  an  acute  point, 
and  found  in  very  different  conditions  in  the  several  stages  of 
life.  In  the  child  it  is  merely  cartilage,  and  we  can  find  no 
point  of  bone  ; during  youth  it  is  ossifying  into  distinct  bones, 
which  continue  moveable  upon  each  other,  till  manhood  : then 
the  separate  bones  gradually  unite  with  each  other,  so  as  to 
form  one  conical  bone,  which  bulgingsand  marks  of  the  pieces 
of  which  it  was  originally  composed  ; but  still  the  last  bone 
continues  to  move  upon  the  joint  of  the  sacrum,  till,  in  ad- 
vanced years,  it  is  at  last  firmly  united,  later  in  women  than  in 
men,  with  whom  it  is  often  fixed  at  twenty  or  twenty-five. 
The  first  bone  is  flat,  with  two  transverse  process  ; the  others 
become  gradually  of  a roundish  form,  convex  without,  and 
concave  inwards,  forming,  with  the  sacrum,  the  lowest  part 
of  the  pelvis  behind.  It  has  no  distinct  holes,  but  the  last  sa- 
cral hole  is  frequently  completed  by  a groove  on  the  upper 
surface  of  the  first  bone ; it  has  no  communication  with  the 
spinal  canal,  but  points  forwards  to  support  the  lower  part  of 
the  rectum ; thus,  it  contracts  the  lower  opening  of  the  pelvis, 
so  as  to  support  effectually  the  rectum,  bladder,  and  womb, 
and  yet  continues  so  moveable  in  women,  as  to  recede  in  time 
of  labour,  allowing  the  head  to  pass. 

The  OSSA  iNNOMiNATA — Are  the  two  great  irregular  bones, 
forming  the  sides  of  the  pelvis,  which  have  a form  so  difficult 
to  explain  by  one  name,  that  they  are  called  ossa  innominata, 
the  nameless  bones.  But  these  bones  having  been  in  the 
child  formed  in  distinct  and  separate  pieces,  these  pieces  re- 
tain their  original  names,  though  united  into  one  great  bone : 
we  continue  to  explain  them  as  distinct  bones,  by  the  names 

VOL.  I.  M 


90 


OF  THE  THUNK. 


of  os  iliuiM,  os  ischium,  and  os  pubis.  The  os  ilium,  the 
haunch-bonc,  is  that  broad  and  expanded  bone  on  which  lie 
the  strong  muscles  of  the  thigh,  and  which  forms  the  round- 
ing of  the  haunch.  The  os  ischium,  the  hip-bone,  the  lowest 
point  of  the  pelvis,  that  on  which  vve  rest  in  sitting.  The  os 
PUBIS,  or  share-bone,  on  which  the  private  parts  are  placed. 
All  these  bones  are  divided  in  the  child ; they  are  united  in 
the  very  centre  of  the  socket  for  the  thigh-bone  ; and  we  find 
in  the  child  a thick  cartilage  in  the  centre  of  the  socket,  and  a 
prominent  ridge  of  bone  in  the  adult ; which  ridge,  far  from  in- 
commoding the  articulation  with  the  thigh-bone,  gives  a firmer 
hold  to  the  cartilage  which  lines  that  cavity,  and  is  the  point 
into  which  a strong  ligament  from  the  head  of  the  thigh-bone 
is  implanted. 

The  os  ILIUM,  or  haunch-bone,  is  named  from  its  forming 
the  flank.  It  is  the  largest  part  of  the  os  innorninatum.  It 
rises  upwai’ds  from  the  pelvis  in  a broad  expanded  iving,  which 
forms  the  lower  part  of  the  cavity  of  the  abdomen,  and  sup- 
ports the  chief  weight  of  the  impregnated  womb  (for  the 
womb  commonly  inclines  to  one  side.)  The  os  ilium  is  cover- 
ed with  the  great  muscles  that  move  the  thighs,  and  to  its 
edge  arc  fixed  those  broad  flat  muscles  which  form  the  walls 
of  the  abdomen.  This  flat  upper  part  is  named  the  ala,  or 
WING,  while  the  lower,  or  rounder  part,  is  named  the  body  of 
the  bone,  where  it  enters  into  the  socket,  and  meets  the  other 
bones. 

The  ALA,  or  flat  expanded  wing,  has  many  parts  which  must 
be  well  remembered,  to  understand  the  muscles  which  arise 
from  them.  1.  The  whole  circle  of  this  wing  is  tipt  with  a 
ridge  of  firmer  bone,  which'  encircles  the  whole.  This  is  a 
circular  cartilage  in  the  child,  distinct  from  the  bone,  and  is 
ossified  and  fixed  only  at  riper  years.  All  this  ridgy  circle  is 
called  the  spine,  and  is  the  origin  for  several  muscles,  2.  The 
two  ends  of  this  spine  are  abrupt,  and  the  points  formed  upon 
it  are  consequently  named  spinous  processes,  of  which  there 
are  two  at  its  fore  and  two  at  its  back  end.  The  two  posteri- 
or SPINOUS  processes  are  close  by  each  other,  and  are  mere- 
ly two  rough  projecting  points  near  the  rough  surface,  hy 
which  the  os  ilium  is  joined  to  the  os  sacrum;  they  jut  out 
behind  the  articulation,  to  make  it  firm  and  sure ; and  their 
chief  uses  seem  to  be  the  giving  a firm  hold  to  the  strong  li- 
gaments which  bind  this  joint.  3.  The  two  anterior  spinous 
processes  arc  more  distinct,  and  more  important  marks;  foy 
the  ANTERIOR  SUPERIOR  SPINOUS  PROCESS,  is  the  abrupt  end- 
ing of  the  spine,  or  circle  of  the  ilium,  with  a swelling  out; 
from  which  jutting  point  the  sartorious  muscle,  the  longest 


OF  THE  TRUNK. 


91 


and  amongst  the  most  beautiful  in  the  human  body,  goes 
obliquely  across  the  thigh,  like  a|  strap,  down  to  the  knee ; 
another,  which  is  called  the  tenser  vagina;  femoris,  also  arises 
here  ; and  from  this  point  departs  the  ligament,  which  passing 
from  the  os  ilium  to  the  pubis,  or  fore  point  of  the  pelvis,  is 
called  the  ligament  of  the  thigh ; how  necessary  it  is  to  mark 
this  point,  may  be  easily  deduced,  from  knowing  that  it  is  un- 
der the  arch  of  this  femoral  ligament  that  the  great  artery 
passes  down  to  the  thigh,  and  that  the  femoral  hernia  is  form- 
ed. The  LOWER  ANTERIOR  spinous  process  is  a small  bump, 
or  little  swelling,  about  an  inch  under  the  first  one,  which 
gives  rise  to  the  rectus  femoris  muscle,  or  straight  muscle  of 
the  thigh,  which  lies  along  its  fore  part,  and  upon  the  inside 
there  is  a depression  lodging  the  iliacus  internus  and  psoas 
magnus. 

The  back,  or  dorsum  of  the  os  ilium,  is  covered  with  the 
three  great  glutaei  muscles;  we  remark  in  a strong  bone  a se- 
micircular ridge  which  runs  from  the  upper  part  of  the  anteri- 
or inferior  spinous  process,  to  the  lower  part  of  the  bone  (the 
notch.)  The  inner  surface  is  hollowed,  so  as  to  be  called  the 
cup  or  hollow,  or  sometimes  the  venter. 

This  bone  (the  os  ilium)  has  a broad  rough  surface,  by 
Avhich  it  is  connected  with  the  os  sacrum  at  its  side,  the  very 
form  of  which  declares  the  nature  of  this  joining,  and  is  suffi- 
cient argument  and  proof  that  the  joinings  of  the  pelvis  do  not 
move. 

The  acute  line,  which  is  named  linea  innominata,  is  seen 
upon  the  internal  surface  of  the  bone,  dividing  the  ala,  or  wing, 
from  that  part  which  is  in  the  socket  for  the  thigh.  This  line 
composes  part  of  the  brim  of  the  pelvis,  distinguishes  the  ca- 
vity of  the  pelvis  from  the  cavity  of  the  abdomen,  and  marks 
the  circle  into  which  the  head  of  the  child  descends  at  the 
commencement  of  labour. 

We  find  particularly  on  the  dorsum  many  irregular  ridges 
for  the  origin  of  muscles,  and  in  many  parts  of  the  bone  we 
see  holes  for  transmitting  vessels;  we  find  one  particularly 
large  in  the  cup. 

The  os  ISCHIUM,  or  hip-bone,  is  placed  perpendicularly 
under  the  os  ilium,  and  is  the  lowest  point  of  the  pelvis  upon 
which  we  sit.  It  forms  the  largest  share  of  the  socket,  whence 
the  socket  is  named  acetabulum  ischii,  as  peculiarly  belong- 
ing to  this  bone.  The  bump  or  round  swelling  upon  which 
we  rest  is  named  the  tuber  ischii ; and  the  smaller  part,  which 
extends  upwards  to  meet  the  os  pubis,  is  named  the  ramus,  or 
branch,  which  meets  a similar  branch  of  that  bone,  to  form 
the  thyroid  hole. 


92 


0F  THE  TRUNK. 


The  BODY  is  the  uppermost,  and  thicker  part  of  the  bone, 
which  helps  in  forming  the  socket;  and  among  the  three 
bones  this  one  forms  the  largest  share  of  it ; nearly  one  half. 
From  the  body,  a sharp  pointed  process  named  spinous  pho- 
CEss  of  the  ischium,  is  projected  backwards,  which  pointing 
towards  the  lower  end  of  the  sacrum,  receives  the  uppermost 
of  two  long  ligaments,  which,  from  their  passing  betwixt  the 
ischium  and  sacrum,  are  named  sacro-sciatic  ; by  this  ligament 
a semi-circle  of  the  os  ilium,  just  below  the  joining  of  the  ili- 
um with  the  sacrum,  is  completed  into  a large  round  hole, 
which  is  in  like  manner  named  the  sacro-sciatic  hole,  and 
gives  passage  to  muscles,  and  to  the  great  nerve  of  the  lower 
extremity,  named  the  great  sacro-sciatic  nerve. 

The  TUBEK,  or  round  knob,  being  the  point  upon  which  we 
rest,  this  bone  has  been  often  named  os  sedentakium.  The 
bump  is  a little  flattened  where  we  sit  upon  it.  It  is  the  mark 
by  which  the  lithotomist  directs  his  incision,  cutting  exactly 
in  the  middle  betwixt  the  anus  and  this  point  of  bone.  It 
is  remarkable  as  the  point  towards  which  the  posterior  or 
lower  sacro-sciatic  ligament  extends,  and  as  a point  which 
gives  rise  to  several  of  the  strong  muscles  on  the  back  of  the 
thigh,  and  especially  to  those  which  form  the  ham-strings. 

Between  the  scabrous  surface  on  the  tuber,  and  the  edge  of 
the  acetabulum,  there  is  a smooth  surface  rather  depressed 
which  is  called  the  cervix.  It  is  covered  with  a cartilage 
which  allows  the  tendon  of  the  obturator  to  move  easily. 

The  RAMUS,  or  branch,  rises  obliquely  upwards  and  for- 
wards, to  join  a like  branch  of  the  pubis.  This  branch,  or 
arm,  as  it  is  called,  is  fiat,  and  its  edges  are  turned  a little  for- 
wards and  backwards,  so  that  one  edge  forms  the  arch  of  the 
pubis,  while  the  other  edge  forms  the  margin  of  the  thyroid 
hole. 

The  os  PUBIS,  or  share-bone,  is  the  last  and  smallest  piece 
of  the  os  innominatum,  and  is  named  from  the  mons  veneris 
being  placed  upon  it,  and  its  hair  being  a mark  of  puberty. 
It  forms  the  upper,  or  fore  part  of  the  pelvis,  and  completes 
the  brim,  and,  like  the  ischium,  it  also  is  divided  into  three 
parts,  viz.  the  body,  angle,  and  ramus. 

The  body  of  the  os  pubis  is  thick  and  strong,  and  forms 
about  one-fifth  of  the  socket  for  the  thigh-bone.  It  is  not 
only  the  smallest,  but  the  shallowest  part  of  the  socket.  The 
bone  grows  smaller,  as  it  advances  towards  its  angle,  it  again 
grows  broad  and  flat,  and  the  two  bones  meet  with  rough  sur- 
faces, but  with  two  cartilages  interposed.  Over  the  middle  of 
this  bone,  two  great  muscles,  the  iliac  and  psoas  muscles,  pass 
out  of  the  pelvis  to  the  thigh ; and  where  they  run  under  the 


OF  THE  TRUNK. 


9S 

ligament  of  the  thigh,  they  make  the  pubis  very  smooth.  On 
the  angle  or  crest  there  is  a process  which  is  frequently  called 
tuberous  angle  : from  this  process  there  are  two  ridges  traced; 
one  goes  to  meet  the  line  on  the  ilium,  and  forms  the  linea 
ileo  pectinea  ; the  other  goes  down  towards  the  edge  of  the 
acetabulum  ; between  these  two  ridges  there  is  a flat  surface 
giving  origin  to  the  pectineus.  The  ramus,  or  branch,  is  that 
more  slender  part  of  the  pubis,  which,  joining  with  the  branch 
of  the  ischium,  forms  with  it  the  arch  of  the  pubis,  and  the 
edge  of  the  thyroid  hole.  Just  under  the  body  of  the  bone, 
there  is  a groove  which  forms  that  part  of  the  thyroid  hole 
which  transmits  the  obturator  nerve  and  artery. 

This  completes  the  strict  anatomy  of  the  pelvis  ; but  when 
we  consider  the  whole,  it  is  further  necessary  to  repeat,  in  short 
definitions,  certain  points  which  are  oftener  mentioned  as  marks 
of  other  parts. 

The  PROMONTORY  of  the  sacrum  is  the  projection  formed  by 
the  lowest  vertebra  of  the  loins,  and  the  upper  point  of  that 
bone.  The  hollow  of  the  sacrum  is  all  that  smooth  inner 
surface  which  gives  out  the  great  nerves  for  the  legs  and  pel- 
vis. The  LESSER  ANGLE,  in  distinction  from  the  greater  angle 
or  promontory  of  the  sacrum,  is  a short  turn  in  the  bone  near 
where  it  is  joined  with  the  os  coccygis.  The  crest  of  the 
PUBIS  is  a sharper  ridge  or  edge  of  the  bone  over  the  joining 
or  symphysis  pubis.  The  posterior  symphysis  of  the  pelvis 
is  the  joining  of  the  sacrum  with  the  ilium,  while  the  symphy- 
sis pubis  is  distinguished  by  the  name  of  anterior  symphysis 
of  the  pelvis.  The  spine,  the  tuber,  and  the  ramus  of  the 
ischium  are  sufficiently  explained.  The  ala,  or  wing,  the 
spine,  the  SPINOUS  processes,  and  the  linea  ini^minata  of 
the  ilium,  are  also  sufficiently  explained.  The  acetabulum, 
so  named  from  its  resemblance  to  a measure  which  the  ancients 
used  for  vinegar,  is  the  hollow  or  socket  for  the  thigh-bone, 
composed  of  the  ilium,  ischium,  and  pubis  ; the  ridge  in  its 
centre  shows  the  place  of  its  original  cartilage,  and  points  out 
what  proportion  belongs  to  each  bone  ; that  it  is  made,  two- 
fifths  by  the  os  ilium,  two-fifths  by  the  os  ischium,  and  one-fifth 
only  by  the  os  pubis  : but  the  ischium  has  the  greatest  share ; 
the  ischium  forming  more  than  two  fifths,  and  the  ilium  less. 
The  cavity,  however,  is  not  entirely  completed  by  bone,  for 
there  is  a ligament  stretched  across  the  inner  and  lower  margin. 

The  BRIM  of  the  pelvis  is  that  oval  ring  which  parts  the 
cavity  of  the  pelvis  from  the  cavity  of  the  abdomen  ; it  is 
formed  by  a continued  and  prominent  line  along  the  upper 
part  of  the  sacrum,  the  middle  of  the  ilium,  and  the  upper 
part  er  crest  of  the  pubis.  This  circle  of  the  brim  supports 


94 


OF  THK  TRUNK. 


the  impregnated  womb,  keeps  it  up  against  the  pressure  of  the 
labour  pains ; and  sometimes  this  line  has  been  “ as  sharp  as 
“ a paper-folder,  and  has  cut  across  the  lower  segment  of  the 
“ womb  and  so,  by  separating  the  womb  from  the  vagina, 
has  rendered  the  delivery  impossible  ; and  the  child  escaping 
into  the  abdomen  among  the  intestines,  the  woman  has  died. 
The  OUTLET  of  the  pelvis  is  the  lower  circle  again,  composed 
by  the  arch  of  the  pubis,  and  by  the  sciatic  ligaments,  which 
is  wide  and  dilatable,  to  permit  the  delivery  of  the  child,  but 
which  being  sometimes  too  wide,  permits  the  child’s  head  to 
press  so  suddenly,  and  with  such  violence  upon  the  soft  parts, 
that  the  perineum  is  torn.  The  thyroid  hole  is  that  remark- 
able vacancy  in  the  bonp  which  perhaps  lightens  the  pelvis,  or 
perhaps  allows  the  soft  parts  to  escape  from  the  pressure,  dur- 
ing the  passage  of  the  head  of  the  child. 

The  marks  of  the  female  skeleton  have  been  sought  for  in 
the  skull,  as  in  the  continuation  of  the  sagittal  suture  5 but  the 
truest  marks  are  those  which  relate  to  that  great  function  by 
which  chiefly  the  sexes  are  distinguished  : for  while  the  male 
pelvis  is  large  and  strong,  with  a small  cavity,  narrow  openings, 
and  bones  of  greater  strength,  the  female  pelvis  is  very  shal- 
low and  wide,  with  a large  cavity,  and  slender  bones,  and  with 
every  peculiarity  which  may  conduce  to  the  easy  passage  of 
the  child.  And  this  occasions  that  peculiar  form  of  the  body 
which  the  painter  is  at  greater  pains  to  mark,  and  which  is  in- 
deed very  easily  perceived ; for  the  characteristic  of  the  manly 
form  is  firmness  and  strerigth ; the  shoulders  broad,  the 
haunches  small,  the  thighs  in  a direct  line  with  the  body,  which 
gives  a firm  and  graceful  step.  The  female  form  again  is 
delicate,  soft,  and  bending ; the  shoulders  are  narrow ; the 
haunches  ttfoad  ; the  thighs  round  and  large ; the  knees  of 
course,  approach  each  other,  and  the  step  is  unsure  : the  wo- 
man even  of  the  most  beautiful  form,  walks  with*  a delicacy 
and. feebleness,  which  we  come  to  acknowledge  as  a beauty  in 
the  weaker  sex. 

The  bones  of  the  pelvis  compose  a cavity  which  cannot  be 
fairly  understood  in  separate  pieces,  but  which  should  be  ex- 
plained as  a whole.  Though  perhaps  its  chief  office  is  sup- 
porting the  spine,  still  its  relation  to  labour  deserves  to  be  ob- 
served ; for  this  forms  at  least  a curious  inquiry,  though  it 
should  not  be  allowed  a higher  place  in  the  order  of  useful 
studies. 

Wc  know,  from  much  experience,  that  where  the  pelvis  is 
of  the  true  size,  w'e  have  an  easy  and  natural  labour : that 
where  tlie  pelvis  is  too  large,  there  is  pain  and  delay  ; but  not 
'hat  kind  of  difficulty  which  endangers  life  ; that  where,  by 


OF  THE  TRUNK. 


95 


distortion,  the  pelvis  is  reduced  below  the  standard  size,  there 
comes  such  difficulty  as  endangers  the  mother,  and  destroys 
the  child,  and  renders  the  art  of  midwifery  still  worthy  of 
serious  study,  and  an  object  of  public  care. 

There  was  a time  when  it  was  universally  believed,  that  the 
joinings  of  the  pelvis  dissolved  in  every  labour  ; that  the  bones 
departed,  and  the  openings  were  enlarged  ; that  the  child 
passed  with  greater  ease  ; and  “ that  this  opening  of  the  basin 
“ w'as  no  less  natural  than  the  opening  of  the  womb.”  By 
many  accidents,  this  opinion  has  been  often  strengthened  and 
revived  ; and  if  authority  could  determine  our  opinion,  we 
should  acknowledge,  that  the  joinings  of  the  pelvis  were  always 
dissolved  as  a wise  provision  of  nature  for  facilitating  natural, 
and  preventing  lingering  labour,  compensating  for  the  frequent 
deviations  btoh  in  the  head  and  pelvis,  from  their  true  and 
natural  size.  This  unlucky  opinion  has  introduced,  at  one 
time,  a practice  the  most  reprehensibly  simple,  as  fomentations 
to  soften  these  joinings  of  the  pelvis  in  circumstances  Avhich 
required  very  speedy  help;  while,  at  another  time,  it  has 
been  the  apology  for  the  most  cruel,  unnatural  operations  of 
instruments,  not  merely  intended  for  dilating  and  opening  the 
soft  parts,  but  for  bursting  up  these  joinings  of  the  bones. 
And  those  also,  of  late  years,  who  have  invented  and  performed 
(too  often,  no  doubt,)  this  operation  of  cutting  the  symphysis 
pubis  to  hasten  the  labour,  say,  that  they  do  not  perform  an 
unnecessary  cruel  operation,  but  merely  imitate  a common 
process  of  nature. 

How  very  far  nature  is  from  intending  this,  may  be  easily 
known  from  the  very  forms  of  these  joinings,  but  much  more 
from  the  other  offices  which  these  bones  have  to  perform ; for 
if  the  pelvis  be,  as  I have  defined  it,  an  arch  standing  betwixt 
the  trunk  and  the  lower  extremities  on  which  the  body  rolls, 
its  joinings  could  not  part  without  pain  and  lameness,  perhaps 
inability  for  life. 

One  chief  reason  drawn  from  anatomy,  is  this : that  in 
women  dying  after  labour,  the  cartilages  of  the  pelvis  are  ma- 
nifestly softened  ; the  bones  loosen ; and  though  they  cannot 
be  pulled  asunder,  they  can  be  shuffled  or  moved  upon  each 
other  in  a slight  degree : all  which  is  easily  accounted  for. 
The  cartilage  that  forms  the  symphysis  pubis  is  not  one  carti- 
lage only,  as  was  once  supposed,  but  a peculiar  caAilage  co- 
vers the  end  of  each  bone,  and  these  are  joined  by  a membra- 
nous or  ligamentous  substance  : this  ligamentous  substance  is 
the  pai;k which  corrupts  the  soonest : it  is  often  spoiled,  and  in 
the  place'  of  it  a hollow  only  is  found  ; that  hollow  of  the  cor- 
rupted ligament  may  be  called  a separation  of  the  bones ; but 


96 


OF  THE  TRUNK. 


it  is  such  a separation  “ as  equals  only  the  back  of  a common 
“ knife  in  breadth,  and  will  not  allow  the  bones  to  depart  from 
“ each  other the  joining  is  still  strong,  for  it  is  surrounded 
by  a capsular  ligament,  is  not  like  the  loose  ligament  of  a 
moveable  joint,  but  adhering  to  every  point  of  each  bone  : 
and  this  ligament  d(»es  perform  its  office  so  completely,  that 
vhile  it  remains  entire,  though  the  bones  shuffle  sideways 
ipon  each  other,  no  force  can  pull  them  asunder : “ Even 

when  the  fore  part  of  the  pelvis  is  cut  out,  and  turned  and 
“ twisted  betwixt  the  hands,  still  though  the  bones  can  be 
“ bent  backwards  and  forwards,  they  cannot  be  pulled  from 
“ each  other  the  tenth  part  of  an  inch.”  These  inquiries 
were  made  by  one,  who,  though  partial  to  the  other  side  of 
this  question,  could  not  allow  himself  to  disguise  the  truth, 
whose  authority  is  the  highest,  and  by  whose  facts  I should 
most  willingly  abide. 

Now,  it  is  plain,  that  since  a separation,  amounting  ony  to 
the  12lh  of  an  inch,  occasions  death,  this  cannot  be  a provi- 
sion of  nature ; and  since  the  separation  in  such  degree  could 
not  enlarge  the  openings  of  the  basin,  there  again  it  cannot  be 
a provision  of  nature.  1 know  that  tales  are  not  wanting  of 
women  whose  bones  were  separated  during  labour;  but  what 
is  there  so  absurd,  that  we  shall  not  find  a precedent  or  paral- 
lel case  in  our  annals  of  monstrous  and  incredible  facts  Or, 
rather,  where  is  there  a fact  of  this  description  which  is  not 
balaneed  and  opposed  by  opposite  authorities  and  facts?  I have 
dissected  several  women  who  have  died  in  lingering  labour, 
where  I found  no  disunion  of  the  bones.  I have  seen  women 
opened,  after  the  greatest  violence  with  instruments,  and  yet 
found  no  separation  of  the  bones.  We  have  cases  of  women 
having  the  mollities  ossium,  a universal  softness,  and  bending 
of  the  bones,  who  have  lived  in  this  condition  for  many  years, 
with  the  pelvis  also  affected  ; its  openings  gradually  more  and 
more  abridged  ; the  miserable  woman  suffering  lingering  la- 
bour, and  undergoing  the  delivery  by  hooks,  with  all  the  vio- 
lence that  must  he  used  in  such  desperate  cases,  and  still  no 
separation  of  the  bones  happening.  How,  indeed,  should 
there  be  such  difficult  labours  as  these,  if  the  separation  of  the 
bones  could  allow  the  child  to  pass  ? 

If  it  be  said,  “ the  joinings  of  the  pelvis  are  sometimes 
dissolved,”  I acknowledge  that  they  are  just  as  the  joint  of  the 
thigh  is  dissolved,  that  is,  sometimes  by  violence,  and  some- 
times by  internal  disease  ; but  if  it  be  affirmed  that  “ the  join- 
“ ings  of  the  pelvis  are  dissolved  to  facilitate  labour,”  I would 
observe,  that  wherever  separation  of  the  bones  has  happened, 
it  has  both  increased  the  difficulties  of  the  labour,  and  been  in 


OF  THE  TRUNK. 


97 


itself  a very  terrible  disease  ; for  proofs  of  which,  I must  refer 
to  Hunter,  Denman,  and  others,  to  whose  peculiar  province 
such  cases  belong.  But  surely  these  principles  will  be  uni- 
versally acknowledged  : that  the  pelvis  supporting  the  trunk  is 
the  centre  of  its  largest  motions  : that  if  the  bones  of  the  pel- 
vis were  loosened,  such  motions  could  nolongerbe  performed : 
that  when,  by  violence  or  by  internal  disease,  or  in  the  time  of 
severe  labour,  these  joinings  have  actually  been  dissolved  or 
burst,  the  woman  has  become  instantly  lame,  unable  to  sit, 
stand,  or  lie,  or  support  herself  in  any  degree  ; she  is  rendered 
incapable  of  turning,  or  even  of  being  turned  in  bed  ; her  at- 
tendants cannot  even  move  her  legs  without  intolerable  an- 
guish, as  if  torn  asunder  :*  there  sometimes  follows  a collec 
tion  of  matter  within  the  joint,  (the  matter  extending  quite 
down  to  the  tuber  ischii),  high  fever,  delirium,  and  death  ;f 
or,  in  case  of  recovery,  (which  is  indeed  more  frequent),  the 
recovery  is  slow  and  partial  only ; a degree  of  lameness  re- 
mains, with  pain,  weakness,  and  languid  health ; they  can 
stand  on  one  leg  more  easily  than  on  both ; they  can  walk 
more  easily  than  they  can  stand ; but  it  is  many  months  before 
they  can  walk  without  crutches;  and  long  after  they  come  to 
walk  upon  even  ground,  climbing  a stair  continues  to  be  very 
difficult  and  painful.  In  order  to  obtain  even  this  slow  re-uni- 
on  of  the  bones,  the  pelvis  must  be  bound  up  with  a circular 
bandage  very  tight;  and  they  must  submit  to  be  confined  long  : 
by  neglect  of  which  precautions,  sometimes  by  the  rubbing 
of  the  bones,  a preternatural  joint  is  formed,  and  they  conti- 
nue lame  for  years,  or  for  life  ;|  or  sometimes  the  bones  are 
united  by  ossification  ; the  callus  or  new  bone  projects  towards 
the  centre  of  the  pelvis,  and  makes  it  impossible  for  the  wo- 
man to  be  delivered  again  of  a living  child, 

Now  this  history  of  the  disease  leads  to  reasons  independent  of 
anatomy,  and  surer  than  it ; which  prove,  that  this  separation 
of  the  bones  (an  accident  the  existence  of  which  cannot  be 
questioned)  is  not  a provision  of  nature,  but  is  a most  serious 
disease.  For  if  these  be  the  dreadful  consequences  of  separa- 
tion of  the  bones,  how  can  we  believe  that  it  happens,  when 
we  see  women  walking  during  all  their  labour,  and,  in  place 
of  being  pained,  are  rather  relieved  by  a variety  of  postures, 
and  by  walking  about  their  room  f who  often  u’alk  to  bed  after 
being  delivered  on  chairs  or  couches who  rise  on  the  third 
day,  and  often  resume  the  care  and  fatigues  of  a family  in  a 

* Denman.  f Huntn. 

t Denman  savf  twenty-five  or  thirty  years. 

? Sneure’s  cases. 

N 


TOL.  r. 


98 


BONES  OF  THE 


few  days  more  r or  can  we  believe,  that  there  is  a tendency 
to  separation  of  the  bones  in  those  who,  following  the  camp, 
are  delivered  on  one  day,  and  walk  on  the»  following  i’  or  in 
those  women  who,  to  conceal  their  shame,  have  not  indulged 
in  bed  a single  hour  ? or  can  we  believe,  that  there  is  even 
the  slightest  tendency  to  the  separation  of  the  bones  in  those 
women  whose  pelvis  resists  the  force  of  a lingering  and  severe 
labour,  who  suffer  still  further  all  the  violence  of  instruments, 
who  yet  recover  as  from  a natural  delivery,  and  who  also  rise 
from  bed  on  the  third  or  fourth  day  ? 


CHAP.  VI. 

BONES  OF  THE  THIGH,  LEG,  ANI>  FOOT. 

r r 

A HE  THIGH-BONE  is  the  greatest  bone  of  the  body,  and 
needs  to  be  so,  supporting  alone,  and  in  the  most  unfavourable 
direction,  the  whole  weight  of  the  trunk ; for  though  the  body 
of  this  bone  is  in  a line  with  the  trunk,  in  the  axis  of  the  body, 
its  neck  stands  off  almost  at  right  angles  with  the  body  of  the 
bone ; and  in  this  unfavourable  direction  must  it  carry  the 
whole  weight  of  the  trunk,  for  the  body  is  seldom  so  placed 
as  to  rest  its  weight  equally  upon  either  thigh-bone ; com- 
monly it  is  so  inclined  from  side  to  side  alternately,  that  the 
neck  of  one  thigh-bone  bears  alone  the  whole  weight  of  the 
body  and  limbs,  or  is  still  loaded  with  greater  burdens  than  the 
mere  weight  of  the  body  itself. 

The  thigh-bone  is  one  of  the  most  regular  of  the  cylindri- 
cal bones.  Its  body  is  very  thick  and  strong,  of  a rounded 
form,  swelling  out  at  either  end  into  two  heads.  In  its  middle 
it  bends  a little  outwards,  with  its  circle  or  convex  side  turned 
towards  the  forepart  of  the  thigh.  This  bending  of  the  thigh- 
bone has  been  a subject  of  speculation  abundantly  ridiculous, 
viz.  w'hether  this  be  an  accidental  or  a natural  arch.  There 
are  authors  who  have  ascribed  it  to  the  nurse  carrying  the 
child  by  the  thighs,  and  its  soft  bones  bending  under  the 
weight.  There  is  another  author,  very  justly  celebrated,  who 
imputes  it  to  the  weight  of  the  body,  and  the  stronger  action 
of  the  flexor  muscles,  affirming,  that  it  is  straight  in  the  child, 
and  grows  convex  by  age.  This  could  not  be,  else  we  should 
find  this  cnrve  less  in  some,  and  greatest  in  those  who  had 


THIGH,  LEG,  AND  FOOT. 


99 


walked  most,  or  whose  muscles  had  the  greatest  strength;  and 
if  the  muscles  did  produce  this  curve,  a little  accident  giving 
the  balance  to  the  flexor  muscles,  should  put  the  thigh-bone 
in  their  power  to  bend  it  in  any  degree,  and  to  cause  distor- 
tion. But  the  end  of  all  such  speculations  is  this,  that  we  find 
it  bended  in  the  foetus,  nor  yet  delivered  from  the  mother’s 
womb,  or  in  a chicken,  while  still  enclosed  in  the  shell ; it  is 
a uniform  and  regular  bending,  designed  and  marked  in  the 
very  first  formation  of  the  bone,  and  intended  perhaps,  for  the 
advantage  of  the  strong  muscles  in  the  back  of  the  thigh,  to 
give  them  greater  power  or  more  room. 

The  HEAD  of  the  thigh-bone  is  likewise  the  most  perfect  of 
any  in  the  human  body,  for  its  circumference  is  a very  regular 
circle,  of  which  the  head  contains  nearly  two-thirds  : it  is 
small,  neat,  and  completely  received  into  its  socket,  which  is 
not  only  deep  in  itself,  and  very  secure,  but  is  further  deepen- 
ed by  the  cartilage  which  borders  it,  so  that  this  is  naturally, 
and  without  the  help  of  ligaments,  the  strongest  joint  in  all  the 
body ; but  among  other  securities  which  are  superadded,  is 
the  round  ligament,  the  mark  of  which  is  easily  seen,  being  a 
broad  dimple  in  the  centre  of  its  head.  In  the  surface  of  the 
head  or  ball  we  observe  a small  pit  for  the  attachment  of  the 
round  ligament  of  the  hip-joint. 

The  NECK  of  this  bone  is  the  truest  in  the  skeleton ; and 
indeed  it  is  from  this  neck  of  the  thigh-bone,  that  we  transfer 
the  name  to  other  bones,  which  have  hardly  any  other  mark 
of  neck  than  that  which  is  made  by  their  purse-like  ligament 
being  fixed  behind  the  head  of  the  bone,  and  leaving  a rough- 
ness there.  But  the  neck  of  the  thigh-bone  is  more  than  an 
inch  in  length,  thick,  and  strong,  yet  hardly  proportioned  to 
the  great  weights  which  it  has  to  bear ; long,  that  it  may  allow 
the  head  to  be  set  deeper  in  its  socket ; and  standing  wide  up 
from  the  shoulders  of  the  bone,  to  keep  its  motions  wide  and 
free,  and  unembarrased  by  the  pelvis ; for  without  this  great 
length  of  the  neck,  its  motions  had  been  checked  even  by  the 
edges  of  its  own  socket. 

The  TROCHANTERS  are  the  longest  processes  in  the  human 
body  for  the  attachment  of  muscles,  and  they  are  named  tro- 
chanter (or  processes  for  turning  the  thigh,)  from  their  office, 
which  is  the  receiving  those  great  muscles  which  not  only 
bend  and  extend  the  thigh,  but  turn  it  upon  its  axis ; for  these 
processes  are  oblique,  so  as  to  bend  and  turn  the  thigh  at 
once. 

The  TROCHANTER  MAJOR,  the  outcimost  and  longer  of  the 
two,  is  that  great  bump  which  represents  the  direct  end  of 
the  thigh-bone,  while  the  neck  stands  off  from  it  at  one  side  ; 


too 


OF  THE  BONES 


therefore  the  great  trochanter  stands  above  the  neck,  and  u' 
easily  distinguished  outwardly,  being  that  great  bump  which  we 
feel  so  plainly  in  laying  the  hand  upon  the  haunch.  On  the 
upper  and  forepart  of  this  great  process,  are  two  surfaces  for 
the  insertion  of  the  gluteus  medius  and  minimus. 

The  extremity  of  the  great  trochanter  hangs  over  a pit  into 
which  principally  the  small  rotator  muscles  of  the  thigh  are  in- 
serted, viz.  the  pyriformis,  the  gernini,  the  obturator  interims 
and  externus.  On  the  lower  part  there  is  a very  strong  mark- 
ed ridge,  which  is  for  the  insertion  of  the  gluteus  maximus. 

The  TKOCHANTER  MINOR,  or  lessci’  trochautcr,  is  a smaller 
and  more  pointed  rising  on  the  inner  side  of  the  bone,  lower 
than  the  trochanter  major,  and  placed  under  the  root  of  the 
neck,  as  the  greater  one  is  placed  above  it.  It  is  deeper  in  the 
thigh,  and  never  to  be  felt,  not  even  in  luxations  Its  muscles 
also,  viz.  the  flexors  of  the  thigh,  by  the  obliquity  of  their  in- 
■sertion  into  it,  turn  the  thigh,  and  bend  it  tov.'ards  the  body, 
such  as  the  psoas  and  iliacus  internus,  which  passing  out  from 
the  pelvis,  sink  deep  into  the  groin,  and  are  implanted  into 
this  point.  From  the  one  trochanter  to  the  other,  there  is  a 
very  conspicuous  roughness,  which  marks  the  place  of  the  cap- 
sule or  ligamentary  bag  of  the  joint;  for  it  encloses  the  whole 
length  of  the  neck  and  of  the  thigh-bone.  This  roughness 
begins  the  great  rough  line,  and  is  what  is  regularly  named 
linea  aspera. 

Betwixt  the  greater  and  lesser  trochanters,  there  runs  a 
rough  line,  the  inter  trochantral  line,  to  which  the  capsular  li- 
gament is  attached,  and  into  which  the  quadratus  femoris  is 
inserted. 

The  LINEA  ASPERA  is  a rising  or  prominent  line,  very  rag- 
ged and  unequal,  which  runs  all  down  the  back  part  of  the 
thigi) : it  begins  at  the  roots  of  the  two  trochanters,  and  the 
rough  lines  from  each  trochanter  meet  about  four  inches  down 
the  bone ; thence  the  linea  aspera  runs  down  the  back  of  the 
bone  a single  line,  and  forks  again  into  two  lines,  one  going 
towards  each  condyle,  and  ending  in  the  tubercles  at  the  lower 
end  of  the  bone,  so  that  the  linea  aspera  is  single  in  the  middle, 
and  forked  at  either  end. 

Tiie  CONDYLES  are  the  two  tubers  into  which  the  thigh- 
bone swells  out  at  its  lower  part.  There  is  first  a gentle  and 
gradual  swelling  of  the  bone,  then  an  enlargement  into  two 
broad  and  flat  surfaces,  which  are  to  unite  with  the  next  bone 
in  forming  the  great  joint  of  the  knee.  The  two  tuberosi- 
ties, which,  by  their  flat  faces,  form  the  joint,  swell  out  above 
the  joint,  and  are  called  the  condyles.  The  inner  condyle 
is  larger,  to  compensate  for  the  oblique  position  of  the  thigh- 


10} 


THIGH,  LEG,  AND  FOOT. 

bone ; for  the  bones  are  separated  at  their  beads,  by  the 
whole  width  of  the  pelvis,  but  are  drawn  towards  a point  be- 
low, so  as  to  touch  each  other  at  the  knees.  On  the  forepart 
of  the  bone,  betwixt  the  condyles,  there  is  a broad  smooth  sur- 
face, upon  which  the  rotula,  or  pulley-like  bone  glides.  The 
outer  side  of  this  trochlea  is  the  largest  and  most  prominent. 
On  the  back  part  of  the  thigh-bone,  in  the  middle,  betwixt  the 
condyle,  there  is  a deep  notch,  which  gives  passage  to  the 
great  artery,  vein,  and  nerve  of  the  leg. 

The  great  nutritious  artery  enters  below  the  middle  of  this 
bone,  and  smaller  arteries  enter  through  its  porous  extremities ; 
as  may  be  known  by  many  small  holes,  near  the  head  of  the 
bone. 

The  HEAD  of  the  thigh-bone  is  round,  and  set  down  deeply 
in  its  socket,  to  give  greater  security  to  a joint  so  impor- 
tant, and  so  much  exposed  as  the  hip  is.  The  neck  stands 
off  from  the  rest  of  the  bone,  so  that  by  its  length  it  allows 
a free  play  to  the  joint,  but  is  itself  much  exposed  by  its  trans- 
verse position,  as  if  nature  had  not  formed  in  the  human 
body  any  joint  at  once  free,  moving,  and  strong.  The  neck 
is  not  formed  in  the  boy,  because  the  socket  is  not  yet 
deep,  nor  binders  the  motions  of  the  thigh,  and  the  head  is 
fox'med  apart  from  the  bone,  and  is  not  firmly  united  with  it  till 
adult  years,  so  that  falls  luxate  or  separate  the  head  in  young 
people,  but  they  break  the  neck  of  the  bone,  in  those  that  are 
advanced  in  years.  The  thochanteks,  or  shoulders,  are  large, 
to  receive  the  great  muscles  which  are  implanted  in  them,  and 
oblique,  that  they  may  at  once  bend  and  turn  the  thigh.  The 
SDAFT  or  BODV  is  Very  strong,  that  it  may  bear  our  whole 
weight,  and  the  action  of  such  powerful  muscles : and  it  is 
marked  with  the  rough  line  behind,  from  which  a mass  of  flesh 
takes'  its  rise,  which  warps  completely  round  the  lower  part  of 
the  thigh-bone,  and  forms  what  are  called  the  vasti  muscles, 
the  greatest  muscles  for  extending  the  leg.  The  condyles 
swell  out  to  give  a broad  surface,  and  a firm  joining  for  the 
knee.  But  of  all  its  parts,  the  great  trochanter  should  be 
most  particularly  observed,  as  it  is  the  chief  mark  in  luxations 
or  fractures  of  this  bone : for  when  the  greater  trochanter  is 
pushed  downwards,  we  find  the  thigh  luxated  inward  ; when 
the  trochanter  is  higher  than  its  trae  place,  and  so  fixed  that 
it  cannot  roll,  we  are  assured  that  it  is  luxated  ; but  when  the 
trochanter  is  up  wards,  with  the  thigh  rolling  freelj",  we  are  as- 
sured its  neck  is  broken,  the  trochanter  being  displaced,  and 
the  broken  head  remaining  in  its  socket ; but  when  the  tro- 
chanter remains  in  its  place,  we  should  conclude  that  the  joint 
:s  but  little  injured,  or  that  it  is  only  a bruise  of  those  glands 


102 


BONES  OF  THE 


or  mucous  follicles,  which  are  lodged  within  the  socket,  for 
lubricating  the  joint. 

The  TIBIA  is  named  from  its  resemblance  to  a pipe ; the 
upper  part  of  the  tibia,  representing  the  expanding  or  trumpet- 
like end,  the  lower  part  representing  the  flute  end  of  the  pipe. 
The  tibia,  on  its  upper  end,  is  flat  and  broad,  making  a most 
singular  articulation  with  the  thigh-bone  ; for  it  is  not  a ball 
and  socket  like  the  shoulder  or  hip,  nor  a hinge-joint  guarded 
on  either  side  with  projecting  points,  like  the  ankle.  There  is 
no  security  for  the  knee-joint,  by  the  form  of  its  bones,  for 
they  have  plain  flat  heads  ; they  are  broad  indeed,  but  they 
are  merely  laid  upon  each  other.  It  is  only  by  its  ligaments 
that  this  joint  is  strong  ; and  by  the  number  of  its  ligaments  it 
is  a complex  and  delicate  joint,  peculiarly  liable  to  disease. 

The  UPPER  HEAD  of  the  tibia,  is  thick  and  spongy,  and  we 
find  there  two  broad  and  superficial  hollows,  as  if  impressed, 
while  soft,  with  the  marks  of  the  condyles  of  the  thigh-bone  ; 
and  these  slight  hollows  are  all  the  cavity  that  it  has  for  re- 
ceivingthe  thigh-bone,  A pretty  high  ridge  rises  betwixt  these 
two  hollows,  so  as  to  be  received  into  the  interstice  betwixt  the 
condyles,  on  the  back  part,  which  is  the  highest  point  of  the 
ridge.  There  is  a pit  on  the  fore  and  on  the  back  part  for  the 
attachment  of  the  crucial  ligaments.  The  spongy  head  has 
also  a rough  margin,  to  which  the  capsular  ligament  is  tied. 
On  the  fore  part  of  this  bone,  just  below  the  knee,  there  is  a 
bump  for  receiving  the  great  ligament  of  the  patella,  or,  in 
other  words,  the  great  tendon  of  all  the  extensor  muscles  of 
the  leg  ; and  lastly,  there  is  upon  the  outer  side  of  this  spongy 
head,  just  under  the  margin  of  the  joint,  a smooth  articulating 
surface,  (like  a dimple  impressed  with  the  finger,)  for  re- 
ceiving the  head  of  the  fibula.  It  is  under  the  margin  of  the 
joint,  for  the  fibula  does  not  enter  at  all  into  the  knee  joint ; 
it  is  only  laid  upon  the  side  of  the  tibia,  fixed  to  it  by  liga- 
ments, but  not  received  into  any  thing  like  a cavity. 

The  BODY  of  the  bone  is  of  a prismatic  or  triangular  form, 
and  its  three  edges  or  acute  angles  are  very  high  lines  running 
along  its  whole  length.  The  whole  bone  is  a little  twisted  to 
give  a proper  position  to  the  foot.  One  line,  the  anterior  an- 
gle, a little  waved,  and  turned  directly  forwards,  is  what  is 
called  the  shin.  At  the  top  of  this  ridge,  is  that  bump  into 
which  the  ligament  of  the  rotula  or  patella  is  implanted  ; and 
the  whole  length  of  this  acute  line  is  so  easily  traced  through 
the  skin,  that  we  can  never  be  mistaken  about  fractures  of  this 
bone.  Another  line  less  acute  than  this,  is  turned  directly 
backwards;  and  the  third  acute  line,  which  completes  the  tri- 
angular form,  is  turned  towards  the  fibula,  to  receive  a broad 


THIGH,  LEG,  AND  FOOT. 


103 


ligament,  or  interosseous  membrane,  which  ties  the  two  hones 
together. 

The  lower  extremity  of  the  tibia  has  a deep  pit  or  cavity  of 
articulation,  which  is  called  the  scaphoid  cavity;  it  receives 
the  astragalus. 

The  middle  of  the  posterior  surface  of  the  bone  is  hollowed 
for  the  lodgement  of  the  muscles,  which  extend  the  foot,  and 
bend  the  toes  ; and  the  anterior  and  outer  surface  is  hollowed 
by  the  lodgement  of  that  muscle,  which  is  called  tibialis  anti- 
cus,  and  the  long  extensors  of  the  toes. 

On  the  back  part  of  the  bone,  near  its  head,  there  is  a flat 
surface  made  by  the  insertion  of  the  popliteus  muscle,  which 
is  bounded  on  the  lower  part  by  a ridge  giving  origin  to  one  of 
the  flexors. 

The  lower  head  of  the  tibia  composes  the  chief  parts  of 
the  ankle-joint.  The  lower  head  of  the  tibia  is  smaller  than 
the  upper,  in  the  same  proportion,  that  the  ankle  is  smaller  than 
the  knee.  The  pointed  part  of  this  head  of  the  tibia  repre- 
sents the  mouth-piece,  or  flat  part  of  the  pipe,  and  constitutes 
the  bump  of  the  1N^ER  ankle.  The  lower  end  of  the  fibula 
lies  so  upon  the  lower  end  of  the  tibia,  as  to  form  the  outer 
ankle  ; and  there  is  on  the  one  side  of  the  tibia  a deep  hollow, 
like  an  impression  made  with  the  point  of  the  thumb,  which 
receives  the  lower  end  of  the  fibula.  The  acute  point  of  the 
tibia,  named  the  process  of  the  inner  ankle,  passes  beyond  the 
bone  of  the  foot,  and,  by  lying  upon  the  side  of  the  joint, 
guards  the  ankle,  so  that  it  cannot  be  luxated  outward,  with- 
out this  pointed  process  of  the  raaleolus  internus,  or  inner 
ankle,  being  broken. 

On  the  back  of  the  lower  head  of  the  bone  there  is  a groove 
which  transmits  the  tendon  of  the  tibialis  posticus  muscle,  and 
at  its  apex  a pit  giving  origin  to  the  deltoid  ligament. 

On  the  back  part  of  the  tibia,  and  a little  below  its  head, 
we  have  to  observe  the  hole  for  the  transmission  of  the  nutri- 
tious artery,  to  the  centre  of  the  bone.  In  amputation  of  the 
leg,  this  artery  is  sometimes  cut  across  just  where  it  has  entered 
the  bone,  and  the  bleeding  proves  troublesome. 

The  tibia  is  a bone  of  great  size,  and  needs  to  be  so,  for  it 
supports  the  whole  weight  of  the  body.  It  is  not  at  all  as- 
sisted by  the  fibula,  in  bearing  the  weight,  the  fibula,  or  slender 
bone,  being  merely  laid  upon  the  side  of  the  tibia,  for  uses 
which  shall  be  explained  presently.  The  tibia  is  thick,  with 
much  cancelli,  or  spongy  substance  w'ithin ; has  pretty  firm 
plates  without ; is  much  strengthened  by  its  ridges,  and  by  its 
triangular  form  : its  ridges  are  regular  with  regard  to  each 
i?ther,  but  the  whole  bone  is  twisted  as  if  it  had  been  turned 


104 


BOi\£S  OF  THE 


betwixt  tbe  hands  when  soft : this  distortion  makes  the  process 
of  tbe  inner  ankle  lie  not  regularly  upon  the  side  of  that  joint, 
but  a little  obliquely  forward,  determining  the  obliquity 
of  the  foot,  which  must  be  of  much  consequence,  since  there 
are  many  provisions  for  securing  this  turning  of  the  foot,  viz. 
the  oblique  position  of  the  trochanters ; the  oblique  insertion 
of  all  the  muscles,  and  this  obliquity  of  the  ankles  ; tbe  inner 
ankle  advancing  a little  before  the  joint,  and  the  outer  ankle 
receding  in  the  same  degree  behind  it. 

The  FIBULA,  which  is  named  so  from  its  resemblance  to 
the  Roman  clasp,  is  along  slender  bone,  which  is  useful  part- 
ly in  strengthening  the  leg,  but  chiefly  in  forming  the  ankle- 
joint  ; for  the  tibia  only  is  connected  with  the  knee,  while  the 
fibula,  which  has  no  place  in  the  knee-joint,  goes  down  below 
tbe  lower  end  of  the  tibia,  forming  the  long  process  of  the 
outer  ankle. 

The  fibula  is  a long  and  slender  bone,  the  longest  and  slen- 
derest in  the  body.  It  lies  by  the  side  of  the  tibia  like  a 
splint,  so  that  when  at  any  time  the  tibia  is  broken  without 
the  fibula,  or  when  the  tibia  having  spoiled,  becomes  carious, 
and  a piece  of  it  is  lost,  the  fibula  maintains  the  form  of  the 
limb  till  the  last  piece  be  replaced,  or  till  the  fracture  be  firm- 
ly re-united.  It  is  like  the  tibia,  triangular  in  the  middle 
part,  but  square  towards  the  lower  end,  and  has  two  heads, 
which  are  knots,  very  large,  and  disproportioned  to  so  slender 
a bone.  The  sharpest  line  of  the  fibula  is  turned  to  one  sharp 
line  of  the  tibia,  and  the  interosseous  membrane  passes  betwixt 
them.  The  other  lines  or  spines  are  in  the  interstices  of  the 
attachment  of  muscle,  which,  arising  from  this  bone,  are  called 
peronei.  The  bone  lies  in  a line  with  the  tibia,  on  the  outer 
side  of  it,  and  a little  behind  it.  The  upper  head  of  the  fibula 
is  rough  on  the  outer  surface,  for  tbe  insertion  of  the  lateral 
ligament,  and  of  the  biceps  cruris,  smooth  and  light,  with  car- 
tilage within,  and  is  laid  upon  a plain  smooth  surface,  on  the 
side  of  the  tibia,  a little  below  the  knee  ; and  though  the  fibula 
is  not  received  deep  into  the  tibia,  this  want  is  compensated 
for  by  the  strong  ligaments  by  which  this  little  joint  is  tied  by 
the  knee,  being  completely  wrapped  round  with  the  expanded 
tendons  of  those  great  muscles  which  make  up  the  thigh,  by 
the  knee  being  still  farther  embraced  closely  by  the  fascia,  or 
tendinous  expansion  of  the  thigh  5 but  above  all,  by  the  ten- 
dons of  the  outer  ham-strings  being  fixed  into  this  knot  of  the 
fibula,  and  expanding  from  that  over  the  forepart  of  the  tibia. 

The  lower  head  of  the  fibula  is  broad  and  flat,  and  is  let 
pretty  deep  into  the  socket  on  the  side  of  the  tibia;  together, 
they  form  the  ankle-joint  for  receiving  the  bones  of  the  fool. 


THIGfH,  LEG,  AND  FOOT. 


106 


Tlie  extreme  point  of  tlie  thin  extremity  gives  attachment  to 
the  outer  ligament  of  the  joint,  and  is  sometimes  called  the 
coronoid  process.  On  the  back  part  of  this  lower  head,  there 
is  a furrow  which  lodges  the  tendons  of  the  peronei  muscles. 
The  ankle-joint  is  one  of  the  purest  hinge  joints,' and- is  very 
secure  ; for  there  is  the  tibia  at  the  process  of  the  inner  ankle, 
guarding  the  joint  within  ; there  is  the  fibula  passing  the  joint 
still  further,  and  making  the  outer  ankle  still  a stronger  guard 
without.  These  two  points,  projecting  so  as  to  enclose  the 
bones  of  the  foot,  making  a pure  hinge,  prevent  all  lateral  mo- 
tion ; make  the  joint  firm  and  strong,  and  will  not  allow  of  lux- 
ations, till  one  or  both  ankles  be  broken.  We  know  that  there 
is  little  motion  betwixt  the  tibia  and  fibula  | none  that  is 
sensibly  outwardly,  and  no  more  in  truth  than  just  to  give  a 
sort  of  elasticity,  yielding  to  slighter  strains.  But  we  are  well 
assured,  that  this  motion,  thou^  slightest  and  imperceptible, 
is  very  constant ; for  these  jointings  of  the  fibula  with  the 
tibia  are  always  found  smooth  and  lubricated ; and  there  are 
no  two  bones  in  the  body  so  closely  connected  as  the  tibia 
and  fibula  are,  which  are  so  seldom  anchylosed,  (z.  c.)  joined 
into  one  by  disease. 

The  fibula  may  be  thus  defined  : it  is  a Iqng  slender  bone, 
which  answers  to  the  double  bone  of  the  fore-arm,  completes 
the  form,  and  adds  somewhat  to  the  strength  of  the  leg ; it 
gives  a broader  origin  for  its  strong  muscles,  lies  by  the  side  of 
the  tibia  like  a splint;  and,  being  a little  arched  towards  the 
tibia,  supports  it  against  those  accidents  which  would  break  it 
across,  and  maintains  the  foi’m  of  the  leg  when  the  tibia  is  ca- 
rious or  broken;  the  fibula,  though  it  has  little  connection 
with  the  knee,  passes  beyond  the  ankle-joint,  and  is  its  chief 
guard  and  strength  in  that  direction  in  which  the  joint  should 
be  most  apt  to  yield  ; and  in  this  ofiice  of  guarding  the  ankle, 
it  is  so  true,  that  the  ankle  cannot  yield  till  this  guard  of  the 
fibula  be  broken. 

Rotula  or  PATELLA,  OP  KNEE-PAN,  is  a Small  thick  bone,  of 
an  oval,  or  rather  triangular  form.  The  basis  of  this  rounded 
triangle  is  tui’ned  upwards  to  receive  the  four  great  muscles 
which  extend  the  leg ; the  pointed  part  of  this  triangle  is  turned 
downwards,  and  is  tied  by  a very  strong  ligament  to  the  bump 
or  tubercle  of  the  tibia,  just  under  the  knee.  The  convex 
surface  is  rough,  the  concave  smooth,  and  divided  by  a ridge 
into  two  equal  parts : round  the  margin  of  the  bone  there  is  a 
slight  depression  for  the  attachment  of  the  capsular  ligament. 
This  ligament  is  called  the  ligament  of  the  patella,  or  of  the 
tibia,  connecting  the  patella  so  closely,  that  some  anatomist? 
of  the  first  name,  choose  to  speak  of  the  patella  as  a mere 

VOL.  r.  O 


106 


BONES  OF  THE 


process  of  the  tibia,  (as  the  olecranon  is  a process  of  the  ulna,) 
only  flexible  and  loose ; an  arrangement  which  I think  so  far 
right  and  useful,  as  the  fractures  of  the  olecranum  and  of  the 
patella  are  so  much  alike,  especially  in  the  method  of  cure, 
that  they  may  be  spoken  of  as  one  case  ; for  these  two  are  the 
only  exceptions  to  the  common  rules  and  methods  of  setting 
broken  bones. 

The  patella  is  manifestly  useful,  chiefly  as  a lever;  fcr  it  is 
a pulley,  which  is  a species  of  lever,  gliding  upon  the  forepart 
of  the  thigh-bone,  upon  the  smooth  surface  which  is  betwixt 
the  condyles.  The  projection  of  this  bone  upon  the  knee  re- 
moves the  acting  force  from  the  centre  of  motion,  so  as  to 
increase  the  power ; and  it  is  beautifully  contrived,  that  while 
the  knee  is  bent,  and  the  muscles  at  rest,  as  in  sitting,  the  pa- 
tella sinks  down,  concealed  into  the  hollow  of  the  knee.  When 
the  muscles  begin  to  act,  the  patella  begins  to  rise  from  this 
hollow;  in  proportion  as  they  contract,  they  lose  their 
strength,  but  the  patella,  gradually  rising,  increases  the  power; 
and  when  the  contraction  is  nearly  perfect,  the  patella  has 
risen  to  the  summit  of  the  knee,  so  that  the  rising  of  the  pa- 
tella raises  the  mechanical  power  of  the  joint  in  exact  propor- 
tion as  the  contwiction  expends  the  living  contractible  power 
of  the  muscles.  What  is  curious  beyond  almost  any  other  fact 
concerning  the  fractures  of  bones,  the  patella  is  seldom  broken 
by  a fall  or  blow ; in  nine  of  ten  cases,  it  is  rather  torn,  if  we 
may  use  the  expression,  by  the  force  of  its  own  muscles,  while 
it  stands  upon  the  top  of  the  knee,  so  as  to  rest  upon  one 
single  point ; for  while  the  knee  is  half  bended,  and  the  patella 
in  this  dangerous  situation,  the  leg  fixed,  and  the  muscles  con- 
tracting strongly  to  support  the  weight  of  the  body,  or  to  raise 
it  as  in  mounting  the  steps  of  a stair,  the  force  of  the  muscles 
is  equivalent  at  least  to  the  weight  of  a man’s  body  ; and  often, 
by  a sudden  violent  exertion,  their  power  is  so  much  increas- 
ed, that  they  snap  the  patella  across,  as  we  would  break  a stick 
across  the  knee. 

The  TARSUS,  or  instep,  is  composed  of  seven  large  bones, 
which  form  a firm  and  elastic  arch  for  supporting  the  body ; 
which  arch  has  its  strength  from  the  strong  ligaments  with 
which  these  bones  are  joined,  and  its  elasticity  from  the  small 
movements  of  these  bones  with  each  other;  for  each  bone  and 
each  joint  has  its  cartilage,  its  capsule  or  bag,  its  lubricating 
fluid,  and  all  the  apparatus  of  a regular  joint;  each  moves  since 
the  cartdages  are  always  lubricated,  and  the  bones  are  never 
joined  by  anchylosis  with  each  other ; but  the  efieCt  is  rather 
a diffused  elasticity  than  a marked  and  perceptible  motion  in 
any  one  joint. 


THIGH,  LEG,  AND  FOOT. 


107 


The  seven  bones  of  which  the  tarsus  is  composed  are,  1. 
The  ASTKAGALus,  ivliich,  united  with  the  tibia  and  fibula, 
forms  the  ankle-joint,  2.  The  os  calcis,  or  heel-bone, 
which  forms  the  end  or  back  point  of  that  arch  upon  which 
the  body  stands.  3.  The  os  navjculare,  or  boat-like  bone, 
which  joins  three  smaller  bones  of  the  forepart  of  the  tarsus 
to  the  astragalus.  4.  The  os  cuboides,  which  joins  the 
smaller  bones  of  the  forepart  of  the  os  calcis.  The  5th,  6th, 
and  7th,  are  the  smaller  bones  making  the  forepart  of  the  tar- 
sus: they  lie  immediately  under  the  place  of  the  shoe-buckle, 
and  are  named  the  three  cuneiform  bones,  from  their  wedge- 
like shape  ; and  it  is  upon  these  that  the  metatarsal  bones, 
forming  the  next  division  of  the  foot,  are  implanted. 

These  bones  of  the  tarsus  form,  along  with  the  next  rank, 
or  metatarsal  bones,  a double  arch ; first  from  the  lowest  pointof 
the  heel  to  the  ball  of  the  great  toe,  is  one  arch ; the  arch  of 
the  sole  of  the  foot  which  supports  the  body;  and  again,  there 
is  another  arch  within  this,  formed  among  the  tarsal  bones 
themselves,  one  within  another,  (*.  e.)  betwixt  the  astragalus, 
os  calcis,  and  jiaviculare,  through  which  hole  in  my  drawing 
there  is  passed  a pencil.  It  is  this  second  arch  which  gives  a 
perfect  elasticity  to  the  foot,  and  must  prevent  the  bad  effects 
of  leaping,  falls,  and  other  shocks,  which  would  have  broken 
a part  less  curiously  adapted  to  its  office. 

1.  The  ASTRAGALUS  is  the  greatest  and  most  remarkable 
bone  of  the  tarsus,  and  which  the  surgeon  is  most  concerned 
in  knowing.  The  semi-circular  head  of  this  bone  forms  a cu- 
rious and  perfect  pulley  The  circle  of  this  pulley  is  large;  its 
cartilage  is  smooth  and  lubricated  ; it  is  received  deep  be- 
twixt the  tibia  and  fibula,  and  rolls  under  the  smooth  articular 
surface  of  the  latter,  w'hich  being  suited  to  this  pulley  of  the  as- 
tragalus, with  something  of  a boat-like  shape,  is  often  named 
the  scaphoid  cavity  of  the  tibia.  1.  We  remark  in  the  astra- 
galus its  articulating  surface,  which  is  arched,  high,  smooth, 
covered  with  cartilage,  lubricated,  and  in  all  respects  a com- 
plete joint.  Its  form  is  that  of  a pulley,  which,  of  course  ad- 
mits of  but  one  direct  motion,  viz.  forwards  and  backwards. 
2.  We  observe  its  sides,  which  are  plain,  smooth,  and  flat, 
covered  with  the  same  cartilage,  forming  a part  of  the  joint, 
and  closely  locked  in  by  the  inner  and  outer  ankles,  so  as  to 
prevent  luxations,  or  awkward  motions  to  either  side.  3.  We 
observe  two  large  irregular  articulating  surfaces  backwards, 
and  downwards,  by  which  it  is  joined  to  the  os  calcis.  4. 
There  is  on  the  forepart,  or  rather  the  fore  end  of  the  astra- 
galus, a large  round  head,  as  regular  as  the  head  of  the 


108 


BONES  OP  THE 


shoulder-bone  by  which  it'  is  articulated  with  the  scaphoid 
bone. 

POINTS  OF  DEMONSTP-ATION. 

1.  Superior  surface  corresponding  with  the  scaphoid  cavity 
of  the  tibia.  2.  Internal  •articulating  surface  for  the  nialeolus 
internus.  3.  External  articulating  surface  for  the  extremity 
of  the  fibula.  4 Inferior  articulating  surface  joining  with  the 
body  of  the  os  calcis.  5.  Inferior  and  lateral  surface  articu- 
lating also  with  a corresponding  surface  of  the  os  calcis.  6. 
Deep  fossa  dividing  these  two  inferior  articulating  surfaces. 
7.  The  ball  or  anterior  articulating  surface  which  enters  into 
the  socket  of  the  naviculare.  8.  A smooth  part  which  is  like 
a continuation  of  this  last,  but  which  rests  upon  a cord  or 
tendon  which  is  stretched  betwixt  the  os  calcis  and  navi- 
/Culare.  9.  Furrow  for  attachment  of  the  capsular  ligament. 

2.  The  os  CALCIS  is  the  large  irregular  bone  of  the  heel ; it  is  the 
tip  or  end  of  the  arch  formed  by  the  tarsal  or  metatarsal  bones. 
There  is  an  irregular  surface  on  the  highest  part  of  the  pro- 
jection backwards  to  which  the  tendo  achilles  is  inserted.  The 
lo  wer  and  back  part  of  the  bone  is  rough  but  peculiar  in  its 
texture  for  the  attachment  of  the  cartilaginous  and  cellular  sub- 
stance on  which  it  rests.  We  next  notice  an  irregular  articular 
surface,  or  rather  two  surfaces  covered  with  cartilage,  by 
which  this  bone  is  joined  with  the  astragalus.  Another  articu- 
lating surface  by  which  it  is  joined  with  the  os  cuboides.  A 
sort  of  arch  downwards,  under  which  the  vessels  and  nerves 
and  the  tendons  also  pass  on  safely  into  the  sole  of  the  foot, 
and  on  this  part  a depression  for  the  peroneus  longus. 

On  the  upper  surface  of  the  bone,  and  betwixt  the  surfaces 
wiiich  articulate  with  the  astragalus,  there  is  an  irregular  rough 
fossa,  which  is  opposite  to  a corresponding  depression  in  the 
astragalus,  and  which  gives  attachment  to  powerful  ligaments 
which  unite  the  bones,  and,  on  the  lower  and  outer  part,  the 
sinnuosity. 

We  further  notice  the  tubercle  whlcb  stands  internally,  and 
gives  attachment  to  the  ligamentum  inter  os  calcem  naviculare 
et  astragalum. 

3.  The  next  bone  is  named  os  naviculare,  or  os  scaphoi- 
DF.S,  from  a fanciful  resemblance  to  a boat.  But  this  is  a 
name  of  which  anatomists  have  been  peculiarly  fond,  and 
which  they  have  used  vviih  very  little  discretion  or  reserve  : 
the  student  will  hardly  find  any  such  resemblance.  That  con- 
cave side  w’hici)  looks  backwards,  is  pretty  deep,  and  receives 
the  head  of  the  astragalus  : that  fiat  side  which  looks  forwards 


THIGH,  LEG,  AND  FOOT. 


109 


has  not  so  deep  a socket,  but  receives  the  three  cuneiform 
bones  upon  a surface  rather  plain  and  irregular.  From  the 
inner  and  lower  part  of  this  bone  a tubercle  stands  out  for  the 
attachment  of  a powerful  ligament,  already  described. 

The  cuNEiFOHJi  BONES  are  so  named,  because  they  resem- 
ble wedges,  being  laid  to  each  other  like  the  stones  of  an  arch. 
The  most  simple  and  proper  arrangement  is,  1.  2.  and  3.; 
counting  from  the  side  of  the  great  toe  towards  the  middle  of 
the  foot;  but  they  are  commonly  named  thus  : the  first  cu- 
neiform bone,  on  which  the  great  toe  stands  has  its  cutting 
edge  turned  upwards ; it  is  much  larger  than  the  others,  and 
so  is  called  os  cuneiform  magnum.  The  second  cuneiform 
bone,  or  that  which  stands  in  the  middle  of  the  three  cu- 
neiform bones,  is  much  smaller,  and  is  therefore  named  os 
CUNEIFORM  MINIMUM.  The  third  in  order,  of  the  cuneiform 
bones,  is  named  os  cuneiform  meuium.*  These  cuneiform 
bones  receive  the  great  toe  and  the  two  next  to  it.  The 
fourth  and  fifth  toes  are  implanted  upon  the  last  bone  in  the 
row,  the  os  cuboides. 

Os  cuBOiuES. — The  os  cuboides  is  named  from  its  cubical 
figure,  and  is  next  to  the  astragalus  in  size,  greater  than  the 
scaphoid  bone.  The  three  cuneiform  bones  are  laid  regularly 
by  the  side  of  each  other ; and  this  os  cuboides  is  again  laid 
on  the  outer  side  of  the  third  cuneiform  bone  and  joins  it  to 
the  os  calcis.  Its  anterior  point  is  divided  into  two  surfaces 
for  two  metatarsal  bones.  The  place  and  effect  of  the  cuboid 
bone  is  very  curious;  for,  as  it  is  jammed  in  betwixt  the  third 
cuneiform  bone  and  the  os  calcis,  it  forms  a complete  arch 
within  an  arch,  which  gives  at  once  a degree  of  elasticity  and 
of  strength  which  no  human  contrivance  could  have  equalled. 
There  is  first  a great  arch  on  which  the  body  rests,  and  the 
heel  and  the  great  toe  are  the  horns  of  that  bow:  and,  second- 
ly, there  is  a complete  circle  among  the  metatarsal  bones, 
leaving  an  opening  betwixt  the  astragalus  and  the  os  calcis. 
Tbe  os  cuboides  has  several  irregular  depressions  on  its  lower 
surface,  but  one  particularly  marked  for  the  peroneus  longus. 

THE  TOES. — The  last  division  of  the  foot  consists  of  three 
distinct  bones ; and  as  these  bones  are  disposed  in  rows,  they 
are  named  the  first,  second  and  third  phalanges  or  ranks  of  the 
toes. 

* The  confusion  in  these  names  arises  from  sometimes  counting  tlieni  by  their  place,  and 
sometimes  reckoning  according  to  their  size.  It  is  only  in  relation  to  its  size  that  we  call 
one  of  these  bones  os  cuneiforai  medium  ; for  the  os  cuneiform  medium  is  not  in  the  middle 
of  the  three;  it  is  the  middle  bone  with  respect  to  size;  it  is  the  smallest  of  the  cnneiform 
bones  that  stand_in  the  middle  betwixt  the  other  two. 


110 


BONES  OE  THE 


The  great  toe  has  but  two  phalanges ; the  other  toes  have 
three  ranks  of  bones,  which  have  nothing  particular,  only  the 
joints  are  round  and  free,  formed  by  a round  head  on  one  bone, 
and  by  a pretty  deep  hollow  for  receiving  it  in  the  one  above 
it ; they  are  a little  flattened  on  their  lower  side,  or  rather  they 
have  a flattened  groove  which  lodges  the  tendons  of  the  last 
joint  of  the  toes 

Thk  sl  SAMom  BONES  are  more  regularly  found  about  the 
toes  than  any  where  else.  They  are  small  bones,  like  peas, 
found  in  tendons,  at  any  point  where  they  suflier  much  friction ; 
or  rather  they  are  like  the  seeds  of  the  sesamum,  whence  their 
name.  They  are  found  chiefly  at  the  roots  of  the  great  toe, 
and  of  the  thumb  ; at  each  of  these  places  we  find  two  small 
sesamoid  bones,  one  on  each  side  of  the  ball  of  the  great  toe, 
and  one  on  each  side  of  the  ball  of  the  thumb  ; but  these 
bones  do  not  enter  into  the  joint;  they  are  within  the  substance 
of  the  tendons ; perhaps,  like  the  patella,  they  remove  the  act- 
ing force  from  the  centre  of  motion,  and  so,  by  acting  like  pul- 
leys, they  increase  the  power;  perhaps  also  by  lying  at  the 
sides  of  the  joint  in  the  tendons  of  the  shorter  muscles  of  the 
toes,  they  make  a safe  gutter  for  the  long  tendons  to  pass  in. 
They  are  not  restricted  to  the  balls  of  the  great  toe  and  thumb, 
but  sometimes  are  also  found  under  the  other  toes  and  fingers, 
and  sometimes  behind  the  condyles  of  the  knee ; or  in  the 
peron  ci  tendons,  which  run  under  the  sole  of  the  foot.  In 
short,  they  are  so  far  from  being  regular  bones,  that  they  are 
found  only  in  adults,  and  are  so  often  found  in  irregular  places, 
that  they  almost  seem  to  be  produced  by  chance,  or  by  the 
eflect  of  friction. 

Metatarsus, — The  metatarsus,  so  named  from  its  being 
placed  upon  the  tarsus,  consists  of  five  bone.s,  which  differ  very 
little  from  the  first  bones  of  the  fingers.  The  metatarsal  bones 
are  five  in  number ; they  are  rather  flattened,  especially  on 
their  lower  sides,  where  the  tendons  of  the  toes  lie  ; they  have 
a ridge  on  their  upper  or  arched  surface  ; they  are  very  large 
at  their  ends  next  the  tarsus,  where  they  have  broad  flat  heads, 
that  they  may  be  implanted  with  great  security ; they  grow 
smaller  towards  the  toes,  where  again  they  tei’minate,  in  neat 
small  round  heads,  which  receive  the  first  bones  of  the  toes, 
and  permit  of  a very  free  and  easy  motion,  and  a greater  de- 
gree of  rotation  than  our  dress  allow's  us  to  avail  ourselves  of, 
the  toes  being  cramped  together,  in  a degree  that  fixes  them 
all  in  their  places,  huddles  one  above  another,  and  is  quite  the 
reverse  of  that  free  and  strong-like  spreading  of  the  toes,  which 
the  painter  always  represents.  It  should  be  remarked,  that 
the  nearer  extremity  of  the  metatarsal  bone  of  the  little  toe 


THIGH,  LEG,  AND  FOOT. 


Ill 


makes  a salient  angle  projecting  over  the  tarsus,  in  a point 
which  is  easily  felt  outwardly,  on  the  side  of  the  foot.  This 
and  all  the  other  marks  of  the  metatarsal  bones  are  chiefly 
useful  as  directing  us  where  to  cut  in  am  utating  these  bones ; 
and  the  surgeon  will  save  the  patient  much  pain,  and  himself 
the  shame  of  a slow  and  confused  operation,  by  marking  the 
places  of  the  joints.  The  metatarsal  bone  of  the  great  toe  is 
the  strongest  and  shortest.  The  articulating  surface  of  its 
nearer  extremity  is  larger  and  deeper;  and  its  anterior  articula- 
ting surface  is  marked  by  a ridge  which  corresponds  with  the 
interstice  of  the  sesamoid  bones. 


CHAP.  VII. 

BONES  OF  THE  SHOULDER,  ARM,  AND  HAND, 

OF  THE  SCAPULA,  OR  SHOULDER-BLADE. 

This  is  the  great  peculiarity  of  the  superior  extremity,  that 
it  is  connected  not  directly  with  the  trunk,  like  the  thigh-bone 
with  the  haunch,  but  is  hung  by  a moveable  intermediate  bone, 
which  not  only  is  not  immediately  joined  to  the  trunk  by  liga- 
ments, nor  any  other  from  of  connection,  but  is  parted  from  it 
by  several  layers  of  muscular  flesh,  so  that  it  lies  flat,  and 
glides  upon  the  trunk. 

The  SCAPULA  is  a thin  bone,  which  has  originally,  like  the 
skull,  two  tables,  and  an  intermediate  diploe  ; but  by  pressure, 
and  the  action  of  its  own  muscles,  it  grows  gradually  thinner, 
its  tables  are  more  and  more  condensed,  till  in  old  age  it  has 
become  perfectly  transparent,  and  is  supported  only  by  its  pro- 
cesses, and  by  its  thicker  edges ; for  its  spine  is  a ridge  of 
firm  and  strong  bone,  which  rises  very  high,  and  gives  a broad 
origin  and  support  for  its  muscles.  The  acromion  in  which 
the  spine  terminates,  is  a broad  and  flat  process,  a sure  guard 
for  the  joint  of  the  shoulder.  The  coracoid  process  is  a 
strong  but  shorter  process,  which  stands  out  from  the  neck  of 
the  bone ; and  the  costa,  or  borders  of  the  bone,  are  also 
rounded,  firm,  and  strong,  so  that  the  processes  and  borders 
support  the  flat  part  of  the  bone,  which  is  as  thin  as  a sheet  of 
paper,  and  quite  transparent. 


112 


BONES  OF  THE 


There  is  no  part  nor  process  of  the  scapula  which  does  Hot 
require  to  be  very  carefully  marked  ; for  no  accidents  are  more 
frequent  than  luxations  of  the  shoulder;  and  the  various  luxa- 
tions are  explained  best  by  studying  in  the  skeleton,  and  being 
able  to  recognize  on  the  living  body  all  the  processes  and 
projecting  points. 

The  FLAT  SIDE  of  the  scapula  is  smooth,  somewhat  concave, 
and  suited  to  the  convexity  of  the  ribs  : it  is  sometimes  ab- 
surdly called  VENTER.  The  scapula  is  connected  with  no  bone 
of  the  trunk,  tied  by  no  ligaments,  is  merely  laid  upon  the 
chest,  with  a large  mass  of  muscular  flesh  under  it,  upon  which 
it  glides;  for  there  are  below  it  two  layers  of  muscles,  by  one 
of  which  the  shoulder-bone  is  moved  upon  the  scapula,  while 
by  the  other,  the  scapula  itself  is  moved  upon  the  ribs.  The 
muscle,  lying  in  the  hollow  of  the  scapula,  marks  it  with  many 
smooth  hollows,  and  wave-like  risings,  which  are  merely  the 
marks  of  the  origin  of  its  muscles,  but  which  were  mistaken 
even  by  the  great  Vesalius  for  the  impressions  of  the  ribs. 

The  upper  flat  surface  is  like  the  lower  one,  but  that  it  is 
traversed  by  the  spine,  which  is  a very  acute  and  high  ridge 
of  bone  : it  is  called  the  dorsum.  Now  the  spine  thus  travers- 
ing the  bone  from  behind  forwards,  divides  its  upper  surface 
into  two  unequal  parts,  of  which  the  part  above  the  spine  is 
smaller,  and  that  below  the  spine  is  larger.  Each  of  these 
spaces  has  its  name,  one  supra  spinatus,  and  the  other  infra 
spinatus ; and  each  of  them  lodges  a muscle,  named,  the  one 
the  musculus  supra  spinatus  scapulae,  as  being  above  the  spine  ; 
ihe  other  musculus  infra  spinatus  scapulae,  as  being  below  the 
spine.  A third  muscle  is  named  subscapularis,  as  lying  under 
ihe  shoulder-blade,  upon  that  concave  surface  which  is  towards 
the  ribs ; so  that  the  whole  scapula  is  covered  with  broad  flat 
muscles,  whose  offices  are  to  move  the  shoulder-bone  in 
various  directions,  and  which  impress  the  scapula  with  gentle 
risings,  and  hollows  on  its  upper  as  wel}  as  on  its  lower  surface. 

The  TRIANGULAR  form  of  the  scapula  must  be  next  observed. 
The  upper  line  of  the  triangle  is  the  shortest ; it  is  named  the 
COSTA  or  border.  This  superior  costa  of  the  scapula  receives 
those  strong  and  flat  muscles  that  raise  the  shoulder  upwards. 
On  this  superior  edge  is  seen  the  notch,  through  which  a nerve, 
and  sometimes  an  artery  passes.  The  lower  border,  which  is 
named  the  costa  inferior,  or  the  lower  border  of  the  scapula, 
receives  no  muscles  ; because  it  must  be  quite  free,  to 
move  and  glide  as  the  scapula  turns  upon  its  axis,  which  is,  in- 
deed, its  ordinary  movement.  But  it  gives  rise  to  two  smaller 
muscles,  which,  from  being  a little  rounded,  are  named  the 


SHOULDER,  ARM,  Afto  HAND.  113 

musculi  teretes,  which  round  muscles  being  implanted  into  the 
arm-bone,  pull  it  downwards. 

The  long  side  of  the  scaphla,  w'hich  bounds  its  triangular 
form  backwards,  is  named  the  basis  of  the  scapula,  as  it  re- 
presents the  base  of  the  triangle.  This  line  is  also  like  the 
two  borders,  a little  thicker  or  swelled  out ; and  this  edge  re- 
ceives many  powerful  muscles,  which  lie  flat  upon  the  back, 
and  coming  to  the  scapula,  in  a variety  of  directions,  can  turn 
it  upon  its  axis,  sometimes  raising,  sometimes  depressing  the 
scapula ; sometimes  drawing  it  backwards ; and  sometimes 
fixing  it  in  its  place,  according  to  the  various  sets  of  fibres 
which  are  put  into  action. 

The  angles  of  the  scapula  are  two,  the  superior  more  obtuse, 
and  the  inferior  more  acute.  From  the  inferior  angle  the  teres 
major  takes  its  it  origin,  and  the  outer  surface  of  the  bone  is 
made  smooth  by  the  passage  of  the  latissimus  muscle. 

The  GLENOID  or  articulating  cavity  of  the  scapula,  is  on 
the  point  or  apex  of  this  triangle.  The  scapula  is  more  strict- 
ly triangular  in  a child,  for  it  terminates  almost  in  a point  or 
apex ; and  this  articulating  surface  is  a separate  ossification, 
and  is  joined  to  it  in  the  adult.  The  scapula  towards  this  point 
terminates  in  a flat  surface,  not  more  than  an  inch  in  diameter, 
very  little  hollowed,  and  scarcely  receiving  the  head  of  the 
shoulder-bone,  which  is  rather  laid  upon  it  than  sunk  into  it : 
it  is  indeed  deepened  a little  by  a circular  gristle,  which  tips 
the  edges  or  lips  of  this  articulating  surface,  but  so  little,  that 
it  is  still  very  shallow  and  plain,  and  luxations  of  the  shoulder 
are  infinitely  more  frequent  than  of  any  other  bone. 

This  head,  or  glenoid  cavity  of  the  scapula,  is  planted  upon 
a narrower  part,  which  tends  towards  a point,  but  is  finished  by 
this  flat  head  ; this  narrower  part  is  what  is  named  the  neck  of 
the  SCAPULA,  which  no  doubt  sometimes  gives  way,  and  breaks, 
A rough  line  bordering  the  glenoid  cavity  receives  the  capsu- 
lar ligament,  or  rather  the  capsule  arises  from  that  bordering 
gristle,  which  I have  said  tips  this  circle. 

The  SPINE  of  the  scapula  is  that  high  ridge  of  bone  which 
runs  the  whole  length  of  its  upper  surface,  and  divides  it  into 
two  spaces  for  the  origin  of  the  supra  and  infra  spinatus  mus- 
cles. It  is  high,  and  very  sharp,  standing  up  at  one  place  to 
the  height  of  two  inches.  It  is  flattened  upon  the  top,  and 
with  edges,  which,  turning  a little  towards  either  side,  give 
rise  to  two  strong  fasciae  {i.  e.)  tendinous  membranes,  which 
go  from  the  spine,  the  one  upwards  to  the  upper  border  of  the 
scapula,  the  other  downwards  to  the  lower  border : so  that  by 
these  strong  membranes,  the  scapula  is  formed  into  two  trian- 
gular cavities,  and  the  supra  and  infra  spinatus  muscles  rise  not 

VOL.  I.  P 


114 


BONES  OP  THE 


only  from  the  back  of  the  scapula,  and  from  the  sides  of  its 
spine,  but  also  from  the  inner  surface  of  this  tense  membrane. 
The  spine  traverses  the  whole  dorsum,  or  back  of  the  scapula; 
it  receives  the  trapezius  muscle,  that  beautiful  triangular  mus- 
cle which  covers  the  neck  like  a tippet,  whence  it  has  its 
name  ; and  the  spine  beginning  low  at  the  basis  of  the  scapula, 
where  a certain  triangular  space  may  be  observed,  gradually 
rises  as  it  advances  forwards,  till  it  terminates  in  that  high  point 
or  promontory  which  forms  the  tip  of  the  shoulder,  and  over- 
hangs and  defends  the  joint. 

This  high  point  is  named  the  acromion  process.  It  is  the 
continuation  and  ending  of  the  spine,  which  at  first  rises  per- 
pendicularly from  the  bone,  but  by  a sort  of  turn  or  distortion, 
it  lays  its  flat  side  towards  the  head  of  the  shoulder-bone : 
here  it  is  hollow,  to  transmit  the  supra  and  infra  spinati  mus- 
cles. At  this  place,  it  is  thickened,  flat  and  strong,  overhangs 
and  defends  the  joint,  and  is  not  merely  a defence,  but  almost 
makes  a part  of  the  joint  itself;  for,  without  this  process,  the 
shoulder-bone  could  not  remain  a moment  in  its  socket ; every 
slight  accident  would  displace  it.  The  acromion  prevents  luxa- 
tion upwards,  and  is  so  far  a part  of  the  joints  that  when  it  is 
full  under  the  acromion,  the  joint  is  safe ; but  when  we  feel  a 
hollow,  so  that  we  can  push  the  points  of  the  fingers  under  the 
acromion  process,  the  shoulder  is  luxated,  and  the  socket 
empty.  The  point  of  the  acromion  forming  the  apex  of  the 
shoulder,  a greater  projection  of  this  point,  and  a fulness  of 
the  deltoid  muscle  which  arises  from  it,  is  a chief  cause,  and 
of  course  a chief  mark  of  superior  strength. 

But  there  is  still  another  security  for  the  joint ; for  there 
arises  from  the  neck  of  the  scapula,  almost  from  the  border 
of  the  socket,  and  its  inner  side,  a thick,  short  and  crooked 
process,  which  stands  directly  forwards,  and  is  very  conspi- 
cuous ; and  which,  turning  forwards  with  a crooked  and  sharp 
point,  somewhat  like  the  back  of  a crow,  is  thence  named  the 
coRACOin  PROCESS.  This  also  guards  and  strengthens  the 
joint ; though  it  cannot  prevent  luxations,  it  makes  them  less 
frequent,  and  most  probably  when  the  arm  is  luxated  inwards 
it  is  by  starting  over  the  point  of  this  defending  process.  This 
process  has  three  surfaces  for  the  attachment  of  muscles. 

Now  the  glenoid  surface,  and  these  two  processes,  form  the 
cavity  for  receiving  the  shoulder-bone.  But  still,  as  if  nature 
could  not  form  a joint  at  once  strong  and  free,  this  joint,  which 
performs  quick,  free,  and  easy  motions,  is  too  superficial  to  be 
strong.  Yet  there  is  this  compensation,  that  the  shoulder-joint, 
w’hich  could  not  resist,  if  fairly  exposed  to  shocks  and  falls,  be- 
longs to  the  scapula,  which,  sliding  easily  upon  the  ribs,  yields, 


SHOULDER,  ARM,  AND  HAND. 


116 


and  so  eludes  the  force.  Falls  upon  the  shoulder  do  not  dis- 
locate the  shoulder;  that  accident  almost  always  happens  to  us 
in  putting  out  the  hand  to  save  ourselves  from  falls  ; it  is  lux- 
ated by  a twisting  of  the  arm,  not  by  the  force  of  a direct 
blow. 

Thk  clavicle. — The  clavicle,  or  collar-bone,  named  clavi- 
cle from  its  resemblance  to  an  old  fashioned  key,  is  to  the  sca- 
pula a kind  of  hinge  or  axis  on  which  it  moves  and  rolls;  so 
that  the  free  motion  of  the  shoulder  is  made  still  freer  by  the 
manner  of  its  connection  with  the  breast. 

The  clavicle  is  placed  at  the  root  of  the  neck,  and  at  the 
upper  part  of  the  breast ; it  extends  across  from  the  tip  of  the 
shoulder  to  the  upper  part  of  the  sternum  ; it  is  a round  bone, 
a little  flattened  towards  the  end  which  joins  the  scapula;  it  is 
curved  like  an  Italic/  having  one  curve  turned  out  towards 
the  breast ; it  is  useful  as  an  arch  supporting  the  shoulders, 
preventing  them  from  falling  forwards  upon  the  breast,  and 
making  the  hands  strong  antagonists  to  each  other,  which, 
without  this  steadying,  they  could  not  have  been. 

The  thoracic  end,  that  end  next  the  sternum,,  or  what  may 
be  called  the  inner  head  of  the  clavicle,  is  round  and  flat,  or 
bulton-like  ; the  articulating  surface  is  triangular,  and  is  re- 
ceived into  a suitable  hollow  on  the  upper  piece  of  the  ster- 
num. It  is  not  only  like  other  joints  surrounded  by  a capsule 
or  purse ; it  is  further  provided  with  a small  moveable  carti- 
lage, which  (like  a friction-wheel  in  machinery)  saves  the  parts, 
and  facilitates  the  motion,  and  moves  continually  as  the  clavi- 
cle rolls.  From  this  inner  head  there  stands  out  an  angle, 
which,  when  the  clavicles  are  in  their  places,  gives  attachment 
to  the  interclavicular  ligament;  it  ties  them  to  the  sternum 
and  to  each  other.  The  lower  surface  has  a groove  in  it  for 
the  subclavius ; the  upper  surface  is  marked  by  several  mus- 
cles. 

But  the  outer  end  of  the  clavicle  is  flattened  as  it  approach- 
es the  scapula,  and  the  edge  of  that  flatness  is  turned  to  the 
edge  of  the  flattened  acromion,  so  that  they  touch  but  in  one 
single  point.  This  outer  end  of  the  clavicle,  and  the  correspond- 
ing point  of  the  acromion,  are  flattened  and  covered  with  a 
crust  of  cartilage ; and  on  the  under  surface  of  it,  there  is  a 
groove  corresponding  to  the  groove  under  the  aci’omion  ; there 
is  also  a small  tubercle  for  a ligament ; but  the  motion  here  is 
very  light  and  quite  insensible  ; they  are  tied  firmly  by  strong 
ligaments;  and  we  may  consider  this  as  almost  a fixed  point; 
for  there  is  little  motion  of  the  scapula  upon  the  clavicle  ; but 
there  is  much  motion  of  the  clavicle  upon  the  breast ; for  the 
clavicle  serves  as  a shaft  or  axis,  firmly  tied  to  the  scapula,  up- 


116 


BONES  OF  THE 


on  which  the  scapula  moves  and  turns,  being  connected  with 
the  trunk  only  by  this  single  point,  viz.  the  articulation  of  the 
clavicle  with  the  breast-bone. 

The  os  HUMERI  is  one  of  the  truest  of  the  cylindrical  bones  j 
it  is  round  in  the  middle  ; but  it  appears  twisted  and  flattened 
towards  the  lower  end  ; and  this  flatness  makes  the  elbow-joint 
a mere  hinge,  moving  only  in  one  direction.  It  is  again  regu- 
lar and  round  towards  the  upper  end,  dilating  into  a large 
round  head,  where  the  roundness  forms  a very  free  and  move- 
able  joint,  turning  easily  in  all  directions. 

The  HEAD  of  this  bone  is  very  large  j it  is  a neat  and  regular 
circle  ; but  it  is  a very  small  portion  of  a large  circle,  so  that 
it  is  flat ; and  this  flatness  of  the  head,  with  the  shallowness 
of  its  glenoid  cavity,  makes  it  a very  weak  joint,  easily  dis- 
placed, and  nothing  equal  to  the  hip-joint  for  security  and 
strength. 

The  NECK  of  this  bone  cannot  fairly  be  reckoned  such  ; for, 
as  I have  explained  in  speaking  of  the  neck  of  the  thigh-bone, 
this  neck  of  the  humerus,  and  the  necks  of  most  bones  (the 
thigh-bone  still  excepted)  are  merely  a rough  line  close  upon 
the  head  of  the  bone,  without  any  straightening  or  intermedi- 
ate narrowness,  which  we  can  properly  call  a neck.  The 
roughness  round  the  head  of  the  shoulder-bone  is  the  line  into 
which  the  capsular  ligament  is  implanted. 

The  TUBEROSITIES  of  the  os  humeri  are  two  small  bumps 
of  unequal  size,  (the  one  called  the  greater,  the  other  the 
smaller  tuberosity  of  the  os  humeri,)  which  stand  up  at  the 
upper  end  of  the  bone,  just  behind  the  head : they  are  not 
very  remarkable.  Though  infinitely  smaller  than  the  tro- 
chanter of  the  thigh-bones,  they  serve  similar  uses,  viz.  re- 
ceiving the  great  muscles  which  move  the  limb.  The  great- 
er TUBEROSITY  is  higher  towards  the  outer  side  of  the  arm, 
and  receives  the  supra  spinatus  muscle;  while  the  infra  spinatus 
and  teres  minor  muscles,  which  come  from  the  lower  part  of 
the  scapula,  are  implanted  into  the  bone  a little  lower.  The 
LESSER  TUBEROSITY  bas  also  a great  muscle  fixed  into  it,  viz. 
the  subscapularis  muscle. 

The  two  tuberosities  form  betwixt  them  a groove,  which  is 
pretty  deep ; and  in  it  the  long  tendon  of  the  biceps  muscle  of 
the  arm  runs : and  as  it  runs  continually,  like  a rope  in  the 
groove  of  a pulley,  this  groove  is  covered  in  the  fresh  bones 
wit!)  a thin  cartilage,  smooth,  and  like  the  cartilages  of  joints. 
On  the  outside  of  this  groove  there  is  a ridge  for  the  pectora- 
lis,  on  the  inside  one  for  the  latissimus.  On  the  body  of  the 
bone,  about  one- third  part  of  its  length  from  the  head,  there  is 
an  irregularity  for  the  attachment  of  the  deltoid  muscle ; and 


SHOULDER,  ARM,  AND  HAND.  Il7 

on  the  inside  of  the  bone,  near  its  middle,  is  the  hole  for  the 
nutritious  artery. 

The  os  humeri  at  its  lower  part  changes  its  form,  is  flattened 
and  compressed  below,  and  is  spread,  out  into  a great  breadth 
of  two  inches  or  more ; where  there  is  formed  on  each  side  a 
sharp  projecting  point,  (named  condyle,)  for  the  origin  of 
great  muscles;  and  in  the  middle,  betwixt  the  two  condyles, 
there  is  a grooved  articulating  surface,  which  forms  the  hinge 
of  the  elbow.  At  the  lower  extremity  the  bone  is  somewhat 
twisted. 

At  the  lower  end  of  the  bone,  there  are  two  ridges,  one  lead- 
to  either  condyle,  which  it  is  of  some  consequence  to  observe  ; 
fo  t':e  elbow-joint  is  a mere  hinge,  the  most  strictly  so  of  any 
jfii  in  the  body:  it  has,  of  course,  but  two  motions,  viz. 
fl(  ion  and  extension;  and  it  has  two  muscles  chiefly,  one  for 
extending,  ttie  otlier  for  bending  the  arm,  : the  flexor  muscle 
lie;,  on  liie  forepart,  and  the  extensor  on  the  back  part  of  the 
ar.ii ; and  so  the  whole  thickness  of  the  arm  is  composed  at 
this  place  of  these  two  muscles  and  of  the  bone  : but  that  the 
fore  and  back  parts  of  the  arm  might  be  thoroughly  divided, 
the  bone  is  flattened  betwixt  them  ; and  that  the  division 
might  extend  beyond  the  mere  edges  of  the  bone,  there  are 
two  fascicE  or  tendinous  webs  which  go  oflf  from  either  edge  of 
the  humerus,  and  which  continue  to  divide  the  fore  from  the 
back  muscles,  giving  these  muscles  a broader  origin  ; they  are 
named,  from  their  office,  intermuscular  membranes ; and  this 
is  the  meaning  of  the  two  ridges  which  lead  to  the  two  con- 
dyles. 

The  two  projections  in  which  these  edges  end,  are  named 
CONDYLCS.  The  condyles  of  the  thigh-bone  are  the  broad 
articulating  surfaces  by  which  that  bone  is  joined  with  the 
tibia,  while  the  condyles  of  the  shoulder-bone  are  merely  two 
sharp  projecting  points  for  the  origin  of  muscles,  which  stand 
out  from  either  side  of  the  joint,  hut  which  have  no  connection 
with  the  joint.  The  chief  use  of  the  condyles  of  the  shoulder- 
hone  is  to  give  a favourable  origin,  and  longer  fulcrum,  for  the 
muscles  of  the  fore-arm,  which  arise  from  these  points.  The 
outer  tubercle  being  the  smaller  one,  gives  origin  to  the  exten- 
sor muscles,  where  less  strength  is  required.  But  the  inner 
tubercle  is  much  longer,  to  give  origin  to  the  flexor  muscles 
with  which  we  grasp,  which  require  a bolder  and  more  pro- 
minent process  to  arise  from  ; for  greater  power  is  needed  to 
perform  such  strong  actions  as  grasping,  bending,  pulling; 
while  the  muscles  which  extend  the  fingers  need  no  more 
power  than  just  to  antagonize  or  oppose  the  flexors ; their  on- 


118 


BONES  OP  THE 


Jy  business  being  to  unfold  or  open  the  hand,  when  we  are  to 
renew  the  grasp. 

It  is  further  curious  to  observe,  that  the  inner  tubercle  is 
also  lower  than  the  other,  so  that  the  articulating  surface  for 
the  elbow-joint  is  oblique,  which  makes  the  hand  fall  naturally 
towards  the  face  and  breast,  so  that  by  being  folded  merely 
without  any  turning  of  the  os  humeri,  the  hands  are  laid  across. 

The  articulating  surface  wliich  stands  betwixt  these  condyles 
forms  a more  strict  and  limited  hinge  than  can  be  easily  con- 
ceived, before  we  explain  the  other  parts  of  the  joint.  The 
joint  consists  of  two  surfaces ; first  a smooth  surface,  upon 
which  the  ulna  moves  only  backwards  and  forwards ; and 
secondly,  of  a small  knob  upon  the  inner  tubercles,  which  has 
a neat  round  surface,  upon  which  the  face  or  socket  belonging 
to  the  button-like  end  of  the  radius  rolls.  These  two  surfaces 
are  called  the  small  head,  and  the  cartilae;inous  pulley  of  the 
humerus. 

Belonging  to  the  joint,  and  within  its  capsular  ligament,  there 
are  two  deep  hollows,  which  receive  certain  processes  of  the 
bones  of  the  fore  arm.  One  deep  hollow  on  the  forepart  of 
the  humerus,  and  just  above  its  articulating  pulley,  receives  the 
liorn-like  or  coronoid  process  of  the  ulna,  viz.  fossa  coronidea ; 
the  other  receives  the  olecranon,  or  that  process  of  the  ulna 
which  forms  the  point  of  the  elbow,  viz.  fossa  olecranalis. 


IIADIUS  AND  ULNA, 

The  radius  and  ulna  are  the  two  bones  of  the  fore  arn).  The 
radius,  named  from  its  resemblance  to  the  ray  or  spoke  of  a 
wheel ; the  ulna,  from  its  being  often  used  as  a measure.  The 
radius  belongs  more  peculiarly  to  the  wrist,  being  the  bone 
which  is  chiefly  connected  with  the  hand,  and  which  turns 
along  with  it  in  all  its  rotatory  motions  : the  ulna,  again,  be- 
longs more  strictly  to  the  elbow-joint,  for  by  it  we  perform  all 
the  actions  of  bending  or  extending  the  arm. 

The  ULNA  is  in  general  of  a triangular  or  prismatic  form, 
like  the  tibia,  and  the  elbow  is  formed  by  the  ulna  alone  ; for 
there  is  a very  deep  notch  or  hinge-like  surface,  which  seems 
as  if  it  had  been  moulded  upon  the  lower  end  of  the  humerus, 
embraces  it  very  closely,  and  takes  so  sure  a hold  upon  the 
humerus,  that  it  allows  not  the  smallest  degree  of  lateral  mo- 
tion, and  almost  keeps  its  place  in  the  dry  skeleton : without 
the  help  of  ligaments  or  muscles,  it  presents,  in  profile,  some- 
what of  the  shape  of  the  letter  S,  and  therefore  is  named  the 
sioMoin  CAvjTv  of  the  ulna.  But  this  sigmoid  cavity  were  a 


SHOULDER,  ARM,  AND  HAND.  1 

very  imperfect  hinge  without  the  two  processes  by  which  it  is 
guarded  before  and  behind  ; the  chief  of  these  is  the  olecra- 
non, or  large  bump,  which  forms  the  extreme  point  upon  which 
we  rest  the  elbow.  It  is  a big  and  strong  process,  which, 
checking  into  a deep  hollow  on  the  back  of  the  humerus,  serves 
tw’o  curious  purposes ; it  serves  as  a long  lever  for  the  muscles 
which  extend  or  make  straight  the  fore  arm  ; and  when  by 
the  arm  being  extended,  it  checks  into  its  place,  it  takes  so 
firm  a hold  upon  the  hinge  or  joint  of  the  os  humeri,  as  to  se- 
cure the  joint  in  pulling,  and  such  other  actions  as  might  cause 
a luxation  forwards.  The  other  process  which  guards  the 
elbow-joint  is  named  the  cokonoid  process,  from  its  horn  or 
poiiited  form ; it  stands  up  perpendicularly  from  the  upper  or 
forepart  of  the  bone  ; it  forms  the  forepart  of  the  sigmoid 
cavity,  and  completes  the  hinge.  On  the  root  of  the  coronoid 
pi’ocess  there  is  a rough  tubercle  for  the  attachment  of  the 
brachialis  internus.  The  coronoid  process  is  useful,  like  the 
olecranon,  in  giving  a fair  hold  and  larger  lever  to  the  muscles, 
and  to  secure  the  joint ; for  the  arm  being  extended,  as  in 
pulling,  the  olecranon  checks  into  its  place,  and  prevents  luxa- 
tion forwards ; and  the  arm  again  being  bent,  as  in  striking, 
pushing  or  saving  ourselves  from  falls,  the  coronoid  process 
prevents  luxation  backwards;  so  the  joint  consists  of  the  olecra- 
non and  the  coronoid  process  as  the  two  guard.s,  and  of  the 
sigmoid  cavity  or  hollow  of  articulation  betwixt  them  ; but  the 
smaller  or  upper  head  of  the  radius  also  enters  into  the  joint, 
and  lying  upon  the  inner  side  of  the  coronoid  process,  it  makes 
a small  hollow  there,  in  which  it  rolls;  and  this  second  hollow, 
touching  the  edge  of  the  sigmoid  cavity,  forms  a double  sig- 
moid cavity,  of  which  the  first,  or  greater  sigmoid  cavity,  is 
for  receiving  the  lower  end  of  the  humerus ; and  the  second, 
or  lesser  sigmoio  cavity,  for  receiving  the  upper  head  of  the 
radius.  Betwixt  these  there  is  a pit  for  receiving  the  glandu- 
lar apparatus  of  the  joint.  The  form  of  the  bone  being  pris- 
matic or  triangular,  it  has,  like  the  tibia,  three  ridges,  one  of 
which  is  turned  towards  a corresponding  ridge  in  the  radius, 
and  betwixt  them  the  interosseous  ligament  is  stretched  ; and 
this  interosseous  ligament  fills  all  the  arch  or  open  space  be- 
twixt the  radius  and  ulna,  and  saves  the  necessity  of  much 
bone;  gives  as  firm  an  origin  to  the  muscles  as  bone  could 
have  done,  and  binds  the  bones  of  the  fore  arm  together  so 
strongly,  that  though  the  ulna  belongs^entirely  to  the  elbow- 
oint,  and  the  radius  as  entirely  to  the  wrist,  they  have  never 
been  known  to  depart  from  each  other.  On  the  outside  of  the 
greater  extremity  of  the  ulna,  there  is  a triangular  surface  for 
the  attachment  of  the  annconeus  muscle.  The  ulna,  bigger 


120 


BONES  OF  THE 


at  the  elbow,  grows  gradually  smaller  downwards,  till  it  termi" 
nates  almost  in  a point.  It  ends  below  in  a small  round  bead, 
which  is  named  the  lowek  head  ol  the  ulna,  which  scarcely 
enters  into  the  joint  of  the  wrist;  but  being  received  into  a 
hollow  on  the  side  of  the  radius,  the  radius  turns  upon  the 
lower  bead  of  the  ulna,  like  an  axis  or  spoke. 

Below  this  little  head,  the  oone  ends  towards  the  side  of  the 
little  linger,  in  a small  rounded  point,  which  is  named  the 
STYLOiD  PROCESS  of  the  ulna.;  it  is  chiefly  useful  in  giving  a 
strong  adhesion  to  the  ligaioent  which  secures  the  wrist  there. 
And  as  the  styloid  process  and  the  olecranon,  the  two  extremi- 
ties of  the  ulna,  are  e-  ^ ' V and  distinctly  felt,  the  length  of  this 
bone  has  been  used  a.  a measure,  and  so  it  was  named  cubitus 
by  the  ancients,  Hud  is  named  ulna  by  us. 

Raimus. — r.'ic  radius  is  the  second  bone  of  the  fore  arm, 
has  its  position  exactly  reversed  with  that  of  the  ulna  : for  the 
ulna,  heiongiog  io  the  elbow,  has  its  greater  end  upwards;  the 
radius,  belonging  to  the  wrist,  has  its  greater  end  downwards; 
and  while  the  ulna  only  bends  the  arm,  the  radius  carries  the 
wrist  with  a rotatory  motion,  and  so  entire!}  belongs  to  the  wrist, 
that  it  is  called  the  manubrium  manus,  as  if  the  handle  of  the 
hand. 

The  BODY  of  the  radius  is  larger  than  that  of  the  ulna.  The 
transverse  strength  of  the  arm  depends  more  upon  the  radius, 
which  has  more  body  and  thickness,  is  more  squared,  and  is 
arched  in  some  degree  so  as  to  stand  off*  from  the  ulna,  with- 
out approaching  it,  or  compressing  the  other  parts.  The 
radius  lies  along  the  upper  edge  of  the  fore  arm,  next  to  the 
thumb,  and  being,  like  the  ulna,  of  a prismatic  or  triangular 
form,  it  has  one  of  its  angles  or  edges  turned  towards  the  ulna 
to  receive  the  interosseous  ligament. 

The  UPPER  HEAD  of  the  radius  js  smaller ; of  a round,  flat- 
fish, and  button-like  shape,  and  lies  so  upon  the  lower  end  of 
the  humerus,  and  upon  the  coronoid  process  of  the  ulna,  that 
it  is  articulated  with  either  bone ; for,  1st,  The  hollow  of  its 
head  is  directly  opposed  to  the  little  head  of  the  os  humeri ; 
and,  2dly,  The  flat  side  of  its  button-like  head  rubs  and  turns 
upon  the  side  of  the  coronoid  process,  making  a socket  there, 
which  is  called  the  lesser  sigmoid  cavity  of  the  ulna. 

Immediately  behind  the  round  fiat  head,  is  a narrowness  or 
straightening,called  the  neck  of  the  radius;  round  this  neck  there 
is  a collar  or  circular  ligament,  (named  the  coronoid  ligament 
of  the  radius,)  which  keeps  the  bone  securely  in  its  place, 
turning  in  this  ligamentous  band  like  a spindle  in  its  bush  or 
socket  ; for  the  radius  has  two  motions,  first  accompanying  the 
ulna  in  its  movements  of  flexion  and  extension ; and,  secondly, 


SHOULDER,  ARM,  AND  HAND.  1^1 

its  own  peculiar  rotation,  in  which  it  is  not  accompanied  in 
return  by  the  ulna  ; but  the  ulna  continuing  steady,  the  radius 
moves,  and  turns  the  wrist. 

luinTediately  under  this  neck,  and  just  below  the  collar  of 
the  bone,  there  is  a prominent  bump,  like  a flat  button  sol- 
dered upon  the  side  of  the  bone,  which  is  the  point  into 
which  the  biceps  flexor  cubiti,  or  bending  muscle  of  the  fore 
arm  is  inserted.  On  the  outside  of  the  bone,  and  near  the 
middle,  there  is  a roughness  for  the  insertion  of  the  pronator. 
Where  the  face  of  the  radius  is  towards  the  ulna,  there  is  a long 
sharp  spine  for  the  attachment  of  the  interrosseous  ligament. 

The  upper  head  is  exceedingly  small  and  round,  while  the 
LOWER  HEAD  swells  out,  broad  and  flat,  to  receive  the  bones 
of  the  wrist.  There  are  two  greater  bones  in  the  wrist,  which 
form  a large  ball,  and  this  ball  is  received  into  the  lower  end 
of  the  radius  : the  impression  which  these  two  bones  make 
there  is  pretty  deep,  and  somewhat  of  a boat-like  shape ; 
whence  it  is  called  (like  the  articulating  surface  of  the  tibia) 
the  scaphoid  cavity  of  the  radius;  it  is  sometimes  partially 
divided  by  a ridge  ; and  on  the  edge  of  the  radius,  next  to  the 
thumb,  the  bone  ends  in  a sort  of  peak  or  sharper  point,  which 
is  named,  (though  with  very  little  meaning,)  the  styloid  pro- 
cess of  the  radius. 

So  the  scaphoid  cavity  of  the  radius  forms  the  joint  with 
the  wrist;  but  there  is  another  small  cavity,  on  the  side  of  the 
radius,  near  to  the  little  head  of  the  ulna,  into  which  the  lesser 
head  of  the  ulna  is  received,  and  this  is  enclosed  in  a proper 
and  distinct  capsule.  The  little  head  of  the  ulna  does  not  de- 
scend so  low  as  to  have  any  share  in  forming  the  wrist.  There 
are  properly  two  distinct  joints ; the  great  joint  of  the  wrist, 
moving  upon  the  radius,  the  other  a little  joint  within  this  of 
of  the  radius,  rolling  upon  the  ulna,  and  carrying  the  wrist 
along  with  it.  On  the  flat  extremity  of  the  radius,  we  find  a 
ridge  in  the  groove ; on  each  side  of  this  spine  the  extensor 
tendons  run.  The  extensors  of  the  thumb  also  make  im- 
pressions. 


OF  THE  HAND  AND  FINGERS. 

The  wrist  is  the  most  complex  part  of  all  the  bony  system, 
and  is  best  explained  in  a general  w'ay,  by  marking  the  three 
divisions  of  the  hand,  into  the  carpus,  or  wrist  bones ; the 
metacarpus,  or  bones  that  stand  upon  the  wrist ; and  the  fin- 
gers, consisting  each  of  its  three  joints.  1.  The  carpus,  or 
wrist,  is  a congeries  of  eight  small  bones,  grouped  together, 
mto  a veiy  narrow  space,  very  firml'v  tied  together,  by  cross 
VOL.  I.  Q 


122 


BONES  OF  THE 


ligaments,  making  a sort  of  ball  or  nuclseus,  a solid  foundation, 
or  centre  for  the  rest  of  the  hand.  2.  The  metacarpus  is 
formed  of  five  long  bones,  founded  upon  the  carpal  bones, 
and  which,  departing  from  that  centre  in  somewhat  of  a radia- 
ted form,  give,  by  their  size  and  strength,  a firm  support  to 
each  individual  finger,  and  by  their  radiated  or  spoke-like,  form 
allow  the  fingers  freer  play.  3.  The  fingers,  consisting  each 
of  three  very  moveable  joints,  are  set  free  upon  the  metacar- 
pus, so  as  to  show  a curious  gradation  of  moving  in  all  these 
parts ; for  the  carpal  bones  are  grouped  together  into  a small 
nuclaeus,  firm,  almost  immoveable,  and  like  the  nave  of  a wheel ; 
then  the  metacarpal  bones  founded  upon  this  are  placed  like 
f the  spokes  or  fellies  of  the  wheel,  and  having  a freer  motion  j 
and,  lastly,  the  fingers  by  the  advantage  of  this  radiated  form, 
ill  the  bones  upon  which  they  are  placed  move  very  nimbly, 
and  have  a rotatory  as  well  as  a hinge-like  motion  ; so  that  the 
motion  is  graduated  and  proportioned  in  each  division  of  the 
hand  ; and  even  where  there  is  no  motion,  as  in  the  carpus, 
there  is  an  elasticity,  which,  by  gentle  bendings,  accommodates 
itself  to  the  more  moveable  parts. 

The  CARPUS,  or  wrist. — Looking  upon  the  external  surface 
of  the  carpus,  we  count  eight  small  bones  disposed  in  two  rows, 
with  one  bone  only  a little  removed  from  its  rank  ; and  we  ob- 
serve that  the  whole  is  arched  outwards  to  resist  injuries,  and 
to  give  strength  ; and  that  the  bones  lie  like  a pavement,  or 
like  the  stones  of  an  arch,  with  their  broader  ends  turned  out- 
wards. On  the  internal  surface,  again,  we  find  the  number  of 
bones  not  so  easily  counted  ; for  their  smaller  ends  are  turned 
towards  the  palm  of  the  hand,  which  being  a concave  surface, 
the  narrow  ends  of  the  wedges  are  seen  huddled  together  in  a 
less  regular  form,  crowded,  and  lapped  over  each  other  5 but 
in  this  hollow,  the  four  corner  bones  are  more  remarkable,  pro- 
jecting towards  the  palm  of  the  hand,  so  as  to  be  named  pro- 
cesses : ^and  they  do  indeed  perform  the  office  of  processes; 
for  there  arises  from  the  four  corner  points  a strong  cross  liga- 
ment, which  binds  the  tendons  down,  and  makes  under  it  a 
floor  or  gutter  for  them  to  run  in. 

The  individual  bones  of  the  carpus  are  small,  cornered,  and 
very  irregular  bones,  so  that  their  names  do  but  very  poorly 
represent  their  form.  To  describe  them  without  some  help 
of  drawing,  or  demonstration,  is  so  very  absurd,  that  a desci’ip- 
tion  of  each  of  them  seems  more  like  a riddle,  than  like  a 
serious  lesson  : it  cannot  be  understood,  and  indeed  it  need 
hardly  be  remembered  ; for  all  that  is  useful,  is  but  to  remem- 
ber the  connection  and  place,  and  the  particular  uses  of  each 
bone  ; in  reading  of  which,  the  student  should  continually  re- 


SHOULDER,  ARM,  AND  HAND.  12S 

turn  to  the  plates,  or  he  must  have  the  bones  always  in  his 
hand. 

1.  ROW  FORMING  THE  WRIST  : viz. 

OS  3CAPHOIDES,  LUNARE,  CUNEIFORME,  MAGNUM,  PISIPORMK. 

Os  scAPHOiDES. — The  boat-like  bone.  This  name  of  boat- 
like bone,  or  boat-like  cavity,  has  been  always  a favourite 
name,  though  a very  unmeaning  one.  The  scaphoid  bone  is 
not  worthy  of  notice  merely  from  its  being  the  largest,  but  also 
as  it  forms  a chief  part  of  the  joint  of  the  wrist;  for  it  is  this 
bone  which  is  received  into  the  scaphoid  cavity  of  the  radius  ; 
it  is  a very  irregular  bone,  in  which  we  need  remember  only 
these  points ; the  large  round  surface  covered  with  cartilage, 
smooth,  and  answering  to  the  cavity  in  the  head  of  the  radius  ; 
the  hook-like  or  projecting  process,  which  forms  one  of  the 
corner  points  of  the  carpus,  and  gives  a hold  to  one  corner  of 
the  ligament  which  binds  down  the  tendons  of  the  wrist. 
There  is  also  a furrow  for  the  capsular  ligament ; the  concavity 
-from  which  this  bone  takes  its  name,  and  by  which  it  is  arti- 
culated with  the  trapezium  and  trapezoides,  and  on  its  inner 
surface  an  oval  cavity  for  the  os  magnum. 

The  os  i.uNARE  is  named  from  one  of  its  sides  being  some- 
what of  the  shape  of  a half  moon  ; it  is  next  in  size  to  the  sca- 
phoid bone,  and  is  equal  to  it  in  importance  ; for  they  are 
joined  together,  to  be  articulated  with  the  radius.  This  bone 
takes  an  equal  share  in  the  joint  with  the  scaphoid  bone  ; and 
together,  they  form  a great  ball,  fitting  the  socket  of  the  radius, 
and  of  a long  form,  so  that  the  wrist  is  a proper  hinge.  The 
chief  marks  of  this  bone  are  its  greater  size,  its  lunated  edge, 
and  its  round  head  forming  the  ball  of  the  wrist-joint.  These 
are  its  surfaces : 

1.  The  surface  of  a semilunar  shape,  and  on  the  radial  side, 
attached  to  the  last  bone.  2.  The  convex  surface  for  articu- 
lation with  the  radius.  3.  The  ulnar  surface  for  articulation 
with  the  os  cuneiforme.  4.  The  hollow  surface  for  articulation 
with  the  os  magnum. 

Tho  os  CUNEIFORME,  Or  wcdge-Hke  bone,  is  named  rather 
perhaps  from  its  situation,  locked  in  among  the  other  bones, 
than  strictly  from  its  form.  Its  side  forming  the  convex  of  the 
hand,  is  broader;  its  point  towards  the  palm  of  the  hand  is 
narrower : and  so  far  we  may  say,  it  is  a wedge-like  bone ; but 
it  is  chiefly  so  from  its  situation  closely  wedged  in  betwixt  tbe 
lunare  and  pisiform  bones. 

1.  We  may  readily  distinguish  the  surface  articulated  with 


124 


BONES  OF  THE 


the  os  lunare.  2,  Opposite  to  this  the  surface  of  attachment 
of  the  os  pisiforrne.  3.  The  further  surface,  that  is,  the  side 
most  remote  from  the  fore  arm,  is  interposed  betwixt  this  bone 
and  the  end  of  the  ulna. 

The  os  pisiFOKMK  is  a small,  neat,  and  round  bone,  named 
sometimes  orbiculak,  or  round  bone,  but  oftener  pisiform, 
from  its  resemblance  to  a pea.  It  is  placed  upon  the  cuneiform 
bone,  and  it  stands  olf  from  the  rest  into  the  palm  of  the  hand, 
so  as  to  be  the  most  prominent  of  all  the  corner  bones ; of 
course,  it  forms  one  of  the  corner  points  or  pillars  of  that  arch, 
under  which  the  tendons  pass.  The  pisiform  bone  is  a little 
out  of  its  rank,  is  very  moveable,  and  projects  so  into  the 
palm,  as  to  be  felt  outwardly,  just  at  the  end  of  the  styloid 
process  of  the  ulna ; it  can  be  easily  moved  and  rolled  about, 
and  is  the  point  into  which  the  ligament  of  the  wrist  is  implan- 
ted, and  the  flexor  carpi  radialis,  one  of  the  strong  muscles 
for  bending  the  wrist. 

2.  ROW  SUPPORTING  THIT METACARPAL  BONES  : viz.  OS  TRA- 
PEZIUM, TRAPEZOIDES,  MAGNUM  ET  UNCIFORME. 

The  second  row  begins  with  the  trapezium,  a pretty  large 
bone,  which,  from  its  name,  we  should  expect  to  find  of  a 
regular  square  form  ; while  it  has,  in  fact,  the  most  irregular 
form  of  all,  especially  when  detached  from  the  other  bones. 
The  chief  parts  to  be  remarked  in  the  bone,  are  the  great 
socket,  or  rather  the  trochlea  for  the  thumb  : and  as  the 
thumb  stands  off  from  one  side  of  the  hand,  this  socket  is  ra- 
ther on  one  side.  There  is  also  a little  process  which  makes 
one  of  the  corner  points,  and  stands  opposite  to  the  hook  of  the 
unciforme. 

Opposite  to  the  surface  of  articulation  with  the  thumb,  and 
towards  the  first  row',  there  is  a semilunar  surface  which 
touches  the  convexity  of  the  scaphoides,  and  another  which 
articulates  w'ith  the  trapezoides.  The  fourth  articulating  sur- 
face of  this  bone  is  opposed  to  the  head  of  the  metacarpal 
bone  of  the  finger. 

The  TRAPEZOiuES  is  next  to  the  trapezium,  is  somewhat 
like  the  trapezium,  from  which  it  has  its  name.  It  also  re- 
sembles the  cuneiform  bone  of  the  first  row  in  its  shape  and 
size,  and  in  its  being  jammed  in  betwixt  the  two  adjoining 
bones. 

It  is  articulated  by  its  nearer  surface  to  the  scaphoides,  on 
its  further  surface,  by  two  planes,  to  the  metacarpal  bone  of 


SHOULDER,  ARM,  AND  HAND.  12.> 

the  fore  finger,  on  the  radial  surface  to  the  trapezium,  and 
on  the  ulnar  surface  to  the  os  magnum,  having  thus  five  planes 
or  surfaces. 

The  os  MAGNUM  is  named  from  its  great  size  ; not  that  it  is 
the  largest  of  all,  nor  even  the  largest  bone  of  the  second  row, 
for  the  unciforme  bone  is  as  big  ; but  there  is  no  other  circum- 
stance by  which  it  is  well  distinguished.  It  is  placed  in  the 
centre  of  the  upper  row,  has  a long  round  head,  which  is 
jointed  with  the  socket  formed  of  the  os  lunare  and  scaphoides: 
on  the  radial  surface  the  magnum  is  articulated  with  the  tra- 
pezoides;  on  the  ulnar  surface  with  the  unciforme;  on  the 
further  surface  it  has  three  planes,  and  receives  the  whole  head 
of  the  metacarpal  of  the  middle  finger,  and  part  of  the  meta- 
carpal of  the  fore  finger  and  of  the  ring  finger. 

The  os  UNCIFORME,  or  hook-like  bone,  is  named  from  a 
flat  hook-like  process,  which  projects  towards  the  palm  of  the 
hand.  This  is  one  of  the  corner  bones,  and  standing  in  the 
end  of  the  row,  it  is  wedged  betwixt  the  os  magnum  of  its  own 
row,  and  the  os  lunare  and  cuneiforme  of  the  first  row.  It  is 
large  and  squared ; but  the  thing  chiefly  remarkable  is  that 
process  from  which  it  takes  its  name ; a long  and  flat  process 
of  firm  bone,  unciforme,  or  hook-like,  and  projecting  far  into 
the  palm  of  the  hand,  which  being  the  last  and  highest  of  the 
corner  points,  gives  a very  firm  origin  to  the  great  ligament 
by  which  the  tendons  of  the  wrist  are  bound  down.  On  its 
further  surface,  it  has  two  articulating  surfaces  corresponding 
with  the  metacarpal  bones  of  the  ring  and  middle  fingers. 

All  these  bones  of  the  carpus,  when  thy  are  joined  to  each 
other,  ai’e  covered  with  a smooth  articulating  cartilage,  are 
bound  to  each  other  by  all  forms  of  cross  ligaments,  and  are 
consolidated,  as  it  were,  into  one  great  joint.  They  are  in 
general  so  firm  as  to  be  scaicely  liable  to  luxation ; and  al- 
though one  only  is  called  cuneiform,  they  are  all  somewhat  of 
the  wedge-like  form,  with  their  broader  ends  outwai’ds,  and 
their  smaller  ends  turned  towards  the  palm  of  the  hand  ; they 
are  like  stones  in  an  arch,  so  that  no  weight  nor  force  can 
beat  them  in  ; if  any  force  do  prevail,  it  can  beat  others  in 
only  by  forcing  one  out.  A bone  starting  outwards,  and  pro- 
jecting upon  the  back  of  the  hand,  is  the  only  form  of  luxation 
among  these  bones,  and  is  extremely  rare. 

METACARPUS. — The  metacarpus  is  composed  of  four 
bones,  upon  which  the  fingers  are  founded.  They  are  big, 
strong  bones,  brought  close  together  at  the  root,  but  wider 
above  ; for  the  lower  beads  are  small  and  flat,  and  grouped 
very  closely  together,  to  meet  the  carpal  bones.  But  they 


126 


BONES  OF  THE 


swell  out  at  their  upper  ends  into  big  round  heads,  which  keep 
the  bones  much  apart  from  each  other.  Nothing  of  impor- 
tance can  be  said  concerning  the  individual  bones.  To  speak 
of  them  individually  is  a mere  waste  of  time.  We  may  observe 
of  the  metacarpal  bones  in  genera!  ; 1.  That  their  nearer 

heads,  being  flat  and  squared,  gives  them  a firm  implantation 
upon  their  centre  or  nuclaius,  the  carpus;  and  they  have  scarce- 
ly any  freer  motion  upon  the  carpal  bones,  than  the  carpal 
bones  have  upon  each  other.  2.  Their  further  heads  are 
broader,  whereby  the  articulating  parts  of  the  bone  are  kept 
apart,  which  gives  freedom  to  the  lateral  motions  of  the  bones 
of  tile  fingers.  3.  Each  metacarpal  bone  is  slightly  bent ; 4. 
and  being  smaller  in  the  middle,  there  is  a space  left  betwixt 
the  bones  for  the  lodgement  of  the  interossii  muscles.  5. 
These  bones  taken  collectively  still  preserve  the  arched  form 
of  the  carpal  bones,  being,  with  the  carpal  bones,  convex 
outwardly,  and  concave  inwardly,  to  form  the  hollow  of  the 
hand;  and  though  they  have  little  motion  of  flexion  or  exten- 
sion, they  bend  towards  a centre,  so  as  to  approach  each  other, 
increasing  the  hollowness  of  the  hand,  to  form  what  is  called 
Diogenes’s  cup.  6.  The  articulating  heads  of  the  further  ex- 
tremities of  these  bones  are  flattened,  or  somewhat  grooved, 
for  the  play  of  the  tendons  of  the  interossii  muscles.  It  is  far- 
ther necessary  to  observe,  into  how  small  a space  the  carpal 
bones  are  compressed,  how  great  a share  of  the  hand  the  me- 
tacarpal bones  form,  and  how  far  down  they  go  into  the  hol- 
low of  the  hand.  For  I have  seen  a surgeon,  who,  not  having 
the  smallest  suspicion  that  their  lower  ends  were  so  near  the 
wrist  as  they  really  are,  has,  in  place  of  cutting  the  bone  neat- 
ly in  its  articulation  with  the  carpus,  broken  it,  or  tried  to  cut 
it  across  in  the  middle. 

FINGERS. — We  commonly  say  that  there  are  five  meta- 
carpal bones ; in  which  reckoning  we  count  the  thumb  with 
the  rest : but  what  is  called  the  metacarpal  of  the  thumb  is 
properly  the  first  phalanx,  or  the  first  proper  bone  of  the  thumb, 
so  that  the  thumb,  regularly  described,  has,  like  the  other  fin- 
gers, three  joints. 

Thumb. — The  first  bone  of  the  thumb  resembles  the  meta- 
carpal bones  in  size  and  strength,  hut  it  differs  widely  in  being 
set  upon  the  carpus,  with  a large  and  round  head ; in  being 
set  off  from  the  line  of  the  other  fingers,  standing  out  on  one 
side,  and  directly  opposed  to  them,  it  rolls  widely  and  freely  : 
it  is  opposed  to  the  other  fingers  in  grasping,  and,  from  its 
very  superior  strength,  the  thumb  is  named  pollex,  from  pol- 
lere. 


SHOULDER,  ARM,  AND  HAND. 


127 


The  FINGERS  have  each  of  them  three  bones  : — 1.  The 
first  bone  is  articulated  with  the  metacarpal  bones  by  a ball 
and  socket ; the  socket,  or  hollow  on  the  lower  part  of  the 
first  finder-bone,  being  set  down  upon  the  large  round  head  of 
the  metacarpal  bone.  2.  The  second  and  third  joints  of  the 
fingers  are  gradually  smaller,  and  though  their  forms  do  a good 
deal  resemble  the  first  joint ; they  are  quite  limited  in  their 
motions  ; haveno  rolling;  are  as  strictly  hinge-joints  as  the  knee 
is.  3.  Here,  as  in  other  hinge-joints,  the  capsule  is  so  particu- 
larly strong  at  the  sides,  as  to  be  named  lateral  ligaments. 
When  these  lateral  ligaments  are  burst  or  cut,  the  finger  turns 
in  any  direction ; so  that  the  motions  of  the  fingers  are  limited 
rather  by  their  lateral  ligaments,  than  by  any  thing  peculiar 
in  the  forms  of  the  bones.  4.  The  face  of  each  finger-bone 
is  grooved,  so  that  the  tendons,  passing  in  the  palm  of  the 
hand  run  upwards  along  this  groove  or  flatness  of  the  fingers ; 
and  from  either  edge  of  this  flatness  there  rises  a ligament  of 
a bridge-like  form  which  covers  the  tendons  like  a sheath, 
and  converts  the  groove  into  a complete  canal.  5.  The  last 
joint  or  phalanx  of  each  finger  is  flattened,  rough,  and  drawn 
smaller  gradually  towards  the  point  of  the  finger ; and  it  is  to 
this  roughness  that  the  skin  and  nail  adhere  at  the  point. 


OF  THE  TEETH.* 

The  structure,  and  growth,  and  decay  of  the  teeth,  forms 
a subject  of  considerable  interest,  as  it  gives  principles  to 
guide  the  operations  of  the  dentist,  and  chiefly  as  it  afibrds 
some  very  remarkable  phenomena  illustrative  of  the  animal 
economy. 

Considering  the  teeth  generally,  as  belonging  to  man  and 
brutes,  they  are  for  masticating  the  food  ; they  are  for  retain- 
ing the  prey ; they  are  weapons  of  defence  ; in  some  classes 
they  are  for  digging  and  searching  for  food ; and  in  some  ani- 
mals we  can  see  no  other  use  than  for  defending  the  eyes,  as 
in  the  sus  aethiopica.  Nor  are  we  to  consider  them  as  exclu- 
sively belonging  to  the  jaws,  for  they  are  sometimes  seated  in 
the  back  part  of  the  mouth  ; and  in  fishes,  we  find  them  in  the 
beginning  of  the  oesophagus,  or  at  its  termination,  as  in  the 
vrab  and  lobster. 


By  diaries  Bell. 


m 


OF  THE  TEETH. 


The  teeth  difler  from  common  bone  : they  are  harder ; they 
are  covered  with  a peculiar  substance,  the  enamel,  which  is 
not  found  elsewhere  in  the  body  : though  they  stand  exposed, 
they  do  not  suffer  as  bone  would  do  in  the  same  circumstan- 
ces ; though  worn  by  friction,  they  are  not  excited  to  diseased 
action  ; their  mode  of  formation  is  peculiar,  and  so  is  the  man- 
ner of  their  decay,  and  all  these  instances  of  their  being  dif- 
ferent from  common  bone,  are  so  many  reasons  for  instituting 
a distinct  enquiry  into  their  structure. 


DESCRIPTION  OF  THE  HUMAN  ADULT  TEETH. 

The  human  adult  teeth  are  divided  into  four  orders.  1, 
The  iNcisoREs.  2.  The  cuspidati  or  canini.  3.  The  bi- 

CUSPIDES.  4.  The  MOLARES  Or  GRINDING  TEETH. 

The  incisores  are  four  in  number  in  each  jaw.  Every 
tooth  has  three  parts ; the  crown,  neck,  and  fang  or  root. 
The  crown  of  the  incisor  tooth  is  a wedge,  having  its  anterior 
and  posterior  surface  inclined  and  meeting  in  a sharp  edge. 
On  the  forepart  the  surface  is  convex ; on  the  inside  the  sur- 
face is  concave ; and  viewing  the  tooth  laterally,  it  is  broader 
and  flat  near  the  neck,  and  rising  pyramidal  towards  the  cut- 
ting edge.  The  cortex  or  enamel  covers  the  crown  of  the 
tooth ; it  descends  on  the  back  and  anterior  surface  further 
than  on  the  side.  The  fangs  of  the  incisores  are  long  and 
straight,  and  of  a pyramidal  form,  so  that  they  are  deeply 
socketed  in  the  jaw. 

From  their  position  in  the  jaw,  the  upper  incisor  teeth  pro- 
ject more  than  the  lower,  and,  in  chewing,  their  edges  do  not 
meet.  They  pass  each  other  so  as  to  cut,  and  yet  do  not 
meet,  and  this  prevents  the  rapid  wasting  of  the  edge  which 
would  otherwise  take  place,  as  we  see  in  the  horse.* 

The  incisor  teeth  of  the  horse,  being  subject  to  attrition, 
have  a provision  against  this,  in  the  cavity  lined  with  enamel, 
which  is  observed  in  their  centre ; nevertheless,  we  see  them 
worn  down  even  below  the  bottom  of  that  cavity ; thus  the 
surface  of  the  tooth  is  smooth,  and  the  horse  has  lost  the 
maik. 

In  some  animals,  as  in  the  rodentia,  the  front  teeth  are  still 
better  formed  for  cutting,  but  as  they  suffer  attrition,  and  in  or- 
der to  preserve  the  outer  edge  sharp,  they  have  a peculiar 
structure.  They  are  so  deeply  socketed,  that  they  reach  the 

* And  as  indeed  we  sonietimcs  see  hi  the  human  tctdi.  See  specimens  in  my  Collec- 
tion. 


0P  THE  TEETH. 


129 


whole  length  of  the  jaw,  and  they  are  provided  with  a continual 
growth  from  behind,  which  pushes  the  tooth  out  in  propor- 
tion as  it  is  worn  away  on  the  forepart.  The  enamel  in  these 
animals  is  more  accumulated  on  the  anterior  edge  of  the  tooth, 
so  that  the  edge  stands  up  fine  and  sharp. 

The  cuspiDATi,  or  canine  teeth,  are  next  in  order,  count- 
ing backwards.  They  are  two  in  number  in  each  jaw.  They 
have  a general  resemblance  to  the  incisor  teeth,  for  when  their 
points  are  worn  off,  they  are  hardly  distinguishable.  Their 
fangs  are  longer,  and  being  the  corner  teeth  of  the  jaw,  and 
deep  socketed,  they  form  the  strength  of  the  front  , teeth. 
Their  principal  distinction  is  in  the  form  of  the  upper  part  of 
the  crown,  which  is  like  a spear,  having  a point  with  two  lateral 
shoulders. 

In  the  larger  carnivorous  mammalia,  this  order  of  teeth  are 
of  terrific  length,  whilst  the  front  teeth  are  small  and  carved. 
The  spiral  tusk  of  the  narwhal  and  the  tusks  of  the  walrus  be- 
long to  this  division  of  the  teeth  : so  does  the  tusk  of  the  barbi- 
roassa,  which  project  in  a spiral  direction.  The  use  of  these 
teeth  Blumenbach  cannot  comprehend,  but  Sir  Everard  Home 
conceives,  that  they  are  provided  to  defend  the  eyes  of  the 
animal  as  it  rushes  through  the  underwood.  There  is  a small 
imperfect  tooth,  called  the  tush,  in  a horse,  which  belongs  to 
this  order  of  teeth,  as  it  is  placed  betwixt  the  incisors  and  the 
grinding  teeth. 

The  BicuspiDES  are  four  in  each  jaw  : they  stand  betwixt 
the  canine  teeth  and  the  grinding  teeth,  and  in  form  are  in- 
termediate betwixt  these  two  orders.  They  are  sometimes 
called  the  lesser  molares,  being  in  truth  grinding  teeth.  The 
crown  of  the  bicuspis  rises  in  two  sharp  points,  so  that  they  are 
like  two  cuspidati  incorporated,  and  their  fangs  prove  this  to 
be  the  case  ; for  whilst  they  are  always  flatter  and  shorter  than 
those  of  the  cuspidati,  they  have  often  a division,  and  some- 
times there  are  distinctly  two  fangs ; their  roots  are  oftener 
curved  than  those  of  the  other  teeth.  The  second  bicuspis  is 
sometimes  wanting. 

Molares  or  grinding  teeth,  are  six  in  each  jaw.  The 
form  of  the  crown  is  an  oblong  square.  They  have  four  or 
more  projections  on  their  upper  surface,  and  they  are  covered 
with  enamel  to  a uniform  level.  The  lower  grinders  have  two 
broad  fangs,  and  those  of  the  upper  jaw  three. 

The  molares  are  best  considered  as  cuspidati  united,  in 
which  idea  four  cuspidati  are  incorporated  to  form  one  grinder. 
The  projections  on  the  grinding  surface  correspond  with  the 
points  of  the  cuspidati,  and  the  fangs  correspond  with  the  pro- 
jections of  the  cro^vn ; for  although  there  are  only  two  or  three 

VOL.  I.  R 


130 


OF  THE  TEETH. 


roots  to  each  grinding  tooth,  yet  we  may  discover  that  there 
would  be  always  four  fangs  if  they  were  disjoined. 

The  term  grinder  is  not  good  in  comparative  anatomy,  for 
in  brutes  of  prey  they  are  compressed,  and  terminate  in  three 
sharp  processes,  and  these  in  the  closing  of  the  jaw  intersect 
each  other  like  the  blades  of  scissars. 

These  four  orders  make  the  full  number  of  thirty-two  in  the 
adult  jaws. 

OP  THE  FIRST  SET  OF  THE  TEETH,  THE  MILK  OR  DECIDUOUS 

TEETH. 

The  first  set  of  teeth  are  twenty  in  number : these  are  divi- 
ded into  three  classes;  the  incisures,  four  in  each  jaw  ; the 
cuspiDATi,  two  in  each  jaw  ; and  the  molares,  four  in  number 
in  each  jaw. 

The  teeth  of  a child  generally  appear  in  this  order  : first 
the  central  incisores  of  the  lower  jaw  pierce  the  gum.  In  a 
month  after,  perhaps,  their  counterparts  appear  in  the  upper 
jaw.  These  in  a few  weeks  are  succeeded  by  the  lateral  in- 
cisores of  the  lower  jaw  ; then  the  lateral  incisores  of  the  up- 
per jaw,  though  sometimes  the  lateral  incisores  of  the  upper 
jaw  appear  before  those  of  the  lower  jaw.  Tlie  growth  of  the 
teeth  is  not  after  this  in  a regular  progression  backwards  ; for 
now,  instead  of  the  cuspidati,  which  are  immediately  lateral  to 
the  incisores,  the  anterior  molares  of  the  lower  jaw  show  their 
white  surface  above  the  gum  about  the  fourteenth  or  fifteenth 
month.  Then  the  cuspidati  pierce  the  gum  ; and  lastly,  the 
larger  molares  make  their  appearance,  the  teeth  of  the  low'er 
jaw  preceding  those  above.  The  last  tooth  does  not  rise  till 
the  beginning  of  the  third  year. 

The  teeth  do  not  always  cut  the  gum  in  this  order ; but  it 
is  the  more  regular  and  common  order.  When  the  teeth  ap- 
pear in  irregular  succession,  more  irritation  and  pain,  and  more 
of  those  symptoms  which  are  usually  attributed  to  teething, 
are  said  to  accompany  them. 

The  deciduous  set  of  teeth  terminates  with  the  rising  of  the 
second  molaris ; for  the  third  molaris  being  formed  about  the 
eighth  year,  when  the  jaw  is  advanced  towards  its  perfect  form, 
is  not  shed,  but  is  truly  the  first  permanent  tooth.  The  mo- 
lares of  the  adult  are  properly  the  permanent  teeth  (immuta- 
BiLEs),  for  they  alone  arise  in  this  part  of  the  jaw,  and  remain 
in  their  original  places;  yet  we  must  recollect  that,  in  oppo- 
sition to  Albinus,  in  this  arrangement,  it  is  more  common  to 
speak  of  the  whole  set  of  the  adult  teeth  as  the  immutabiles. 


OF  THE  TEETH. 


131 


In  the  sixth  and  seventh  years  the  jaws  have  so  much  en- 
larged, that  the  first  set  of  teeth  seems  too  small,  spaces  are 
left  betwixt  them,  and  they  begin  to  fall  out,  giving  place  to 
the  adult  teeth.  But  the  shedding  of  the  teeth  is  by  no  means 
regular  in  regard  to  time;  the  child  is  already  no  longer  in  a 
stale  of  nature,  and  a thousand  circumstances  have  secretly 
alfected  the  health  and  growth.  The  teeth  even  fall  out 
three  years  earlier  in  one  child,  than  in  another:  nay,  so  fre- 
quently are  some  of  them  retained  altogether,  that  it  would 
appear  necessary  to  be'assured  of  the  forward  state  of  the  adult 
tooth  before  the  tooth  of  the  first  set  should  be  thoughtlessly 
drawn. 

The  jaw-bones  are  still  so  small,  that  the  second  set  of  teeth 
must  rise  slowly  and  in  succession,  else  they  would  be  crowd- 
ed into  too  small  a circle,  and  of  course  turned  from  their 
proper  direction. 

The  in'dsores  of  the  under  jaw  are  loose  commonly  when 
the  anterior  of  the  permanent  molares  are  thrusting  up  the 
gum.  The  permanent  central  incisores  soon  after  appear, 
and  in  tw'o  or  three  months  more  those  of  the  upper  jaw  ap- 
pear. In  three  or  four  months  the  lateral  incisores  of  the 
lower  jaw  are  loose,  and  the  permanent  teeth  appear  at  the 
same  time  with  the  anterior  molares.  The  lateral  incisores  of 
the  upper  jaw  follow  next ; and  in  from  six  to  twelve  months 
more,  the  temporary  molares  loosen,  the  long  fangs  of  the  cus- 
pidati  retaining  their  hold  some  time  longer. 

The  anterior  molaris  and  the  cuspidati  falling,  are  succeeded 
about  the  ninth  year  by  the  second  of  the  bicuspides  and  the 
cuspidati.  The  posterior  of  the  bicuspides  take  place  of  the 
anterior  molares  about  the  tenth  or  eleventh  year ; the  second 
permanent  molaris  does  not  appear  for  five  or  six  years  from 
the  commencement  of  the  appearance  of  the  permanent  teeth. 
The  jaw  acquires  its  full  proportion  about  the  age  of  eighteen 
or  twenty,  when  the  third  molaris,  or  the  dens  sapientire,  makes 
its  appearance.  This  tooth  is  shorter  and  smaller,  and  is  in- 
' dined  more  inward  than  the  others.  Its  fangs  are  less  regular 
, and  distinct,  being  often  squeezed  together.  From  the  cus- 
pidati to  the  last  grinder,  the  fangs  are  becoming  much  shorter, 
and  from  the  first  incisor  to  the  last  grinder,  the  teeth  stand 
less  out  from  the  sockets  and  gums. 


OF  THE  STRUCTURE  OF  THE  TEETH. 

A tooth  consists  of  these  parts  : — The  enamel,  a peculiarly 
hard  layer  of  matter  composing  the  surface  of  the  body  of  the 


132 


0F  THE  TEETH. 


tooth.  The  internal  part,  or  inner  substance  of  the  tooth,  is 
less  stony  and  hard  than  the  enamel,  but  of  a firmer  structure 
and  more  compact  than  common  bone.  In  regard  to  the  form 
of  the  tooth,  we  may  observe,  that  it  is  divided  into  the  crown, 
the  neck,  and  the  fangs,  or  roots  of  the  tooth,  which  go  deep 
into  the  jaw.  There  is  a cavity  in  the  body  of  the  tooth,  and 
the  tube  of  the  fangs  communicates  with  it.  This  cavity  re- 
ceives vessels  for  supplying  the  remains  of  that  substance  upon 
which  the  tooth  w'as  originally  formed.  The  roots  of  the 
teeth  are  received  into  the  jaw  by  that  kind  of  articulation 
which  was  called  gomphosis.  They  are  not  firmly  wedged  into 
the  bone,  for  in  consequence  of  maceration,  and  the  destruc- 
tion of  the  soft  parts,  the  teeth  drop  from  the  skull.  There 
is  betwixt  the  tooth  and  its  socket  in  the  jaw  a common  pe- 
riosteum. 

Of  the  enamel.  The  surface  of  a tooth,  that  which  ap- 
pears above  the  gum,  is  covered  with  a very  dense  hard  layer 
of  matter,  which  has  been  called  the  enamel.*  In  this  term 
there  is  some  degree  of  impropriety,  as  assimilating  an  atiimal 
production  with  a vitreous'substance,  although  the  enamel  very 
widely  difiers  from  the  glassy  fracture  when  broken.  This 
matter  bestows  the  most  essential  quality  of  hardness  on  the 
teeth  ; and  when  the  enamel  is  broken  off,  and  the  body  of 
the  tooth  exposed,  the  bony  part  quickly  decays. 

The  enamel  is  the  hardest  production  of  the  animal  body. 
It  strikes  fire  with  steel : in  church-yard  skulls  it  is  observed  to 
remain  undecayed  when  the  centre  of  the  tooth  has  fallen  into 
dust.  It  has  been  found  that  the  component  parts  of  the  ena- 
mel are  nearly  the  same  with  those  of  bone.  In  bone  the 
phosphate  of  lime  is  deposited  on  the  membranes,  or  carti- 
lage, but  this  hardening  matter  of  bones  is  a secretion  from 
the  vessels  of  the  part,  and  is  accumulated  around  the  vessels 
themselves  : it  is  still  within  the  controul  of  their  action,  and 
is  suffering  the  succession  of  changes  peculiar  to  a living  part. 
In  the  enamel,  the  phosphate  of  lime  has  been  deposited  in 
union  with  a portion  of  animal  gluten,  and  has  no  vascularity, 
nor  does  it  suffer  any  change  from  the  influence  of  the  living 
.system.  Although  the  hardening  matter  be  principally  phos- 
phate of  lime,  a small  proportion  of  the  carbonate  of  lime 
enters  into  the  composition  both  of  bone  and  of  enamel.  But 
in  enamel,  according  to  Morichini  and  Gay  Lussac,  there  is 
Jluat  of  lime,  to  which  ingredient  these  chemists  attribute  the 
hardness  of  this  crust, f 

* Jn  brutes  thei'e  is  a considerable  variety  in  the  relative  form  of  the  enamel  and  bone  of 
the  tootli. 

' T By  Mr.  Hatchetts’s  Experiments,  (Philos.  Transact.  1799,)  we  learn  that  bone  con- 
sists of  phasphate  of  lime,  with  a small  propmtion  of  caibonate  of  lime.  The  shell  of  the 


OF  THE  TEETH 


133 


Although  we  call  the  earthy  deposite,  the  hardening  matter, 
yet  it  is  the  union  of  the  glutinous  matter  which  bestows  the 
extreme  hardness,  for,  when  the  tooth  is  as  yet  within  the  jaw, 
and  in  an  early  stage  of  its  formation,  the  depositation  is  soft, 
and  its  surface  rough ; but,  by  a change  of  action  in  the  sur- 
face, which  throws  out  this  secretion,  the  first  depositation  is 
penetrated  with  gelatinous  secretion,  which,  either  by  this 
penetration  simply,  or  by  causing  a new  apposition  of  its  parts, 
(its  structure  indeed  looks  like  chrystallization,)  bestows  the 
density  and  extreme  hardness  on  this  crust. 

When  an  animal  is  fed  with  madder,  the  colouring  matter 
coming,  in  the  course  of  the  circulation,  in  contact  with  the 
earth  of  bone,  is  attracted  by  it,  and  is  deposited  upon  it  in  a 
beautiful  red  colour.  This  colouring  matter  penetrates  more 
than  injection  can  be  made  to  do  in  the  dead  body ; and,  as 
by  this  process  of  feeding,  the  enamel  is  not  tinged,  we  have 
a convincing  proof  that  the  vascular  system  has  no  opei’ation 
on  the  enamel  after  it  is  formed. 

Id  the  marmot,  beaver,  and  squirrel,  the  enamel  is  of  a nut 
brown  colour,  on  the  anterior  surface  of  the  incisor  teeth. 
The  molares  of  some  of  the  cloveh-lioofed  animals  are  cover- 
ed with  a black  vitreous  matter,  and  sometimes  they  have  a 
crust  of  a shining  substance  like  bronze.  In  the  grinding  teeth 
of  the  granivorous  animals,  the  arrangement  of  the  enamel  is 
quite  peculiar. 

From  the  composition  of  the  enamel,  we  must  be  aware  of 
the  bad  elfect  of  acidulated  washes  and  powdei’s  to  the  teeth  ; 
they  dissolve  the  surface,  and  give  a deceitful  whiteness  to 
the  teeth  ; they  erode  the  surface,  which  it  is  not  in  the  consti- 
tution of  the  part  to  restore. 

OF  THE  CENTRAL  BONY  PAKT  OF  THE  TOOTH. 

The  chemical  composition,  and  the  manner  of  combination 

crab  and  lobster  consists  of  phosphate  of  lime  and  carbonate  of  lime,  the  latter  being  in  the 
greatest  quantity.  The  testaceous  shells  comist  entirely  of  carbonate  of  h’me.  The  mat- 
ter of  hone  and  teeth  consists  of  phosphate  of  lime  and  a small  portion  of  carbonate  deposi- 
ted in  the  intei-stice  of  an  animal  substance,  which  is  of  the  nature  of  cartilage,  and  proves 
to  be  gelatine.  The  bones  of  6sh  diflfer  from  those  of  man  and  brutes,  in  the  larger  propor- 
tion of  animal  substance.  These  chemichai  facts  are,  however,  of  little  import  to  the  ana- 
tomist : he  is  desirous  of  knowinv  what  property  of  life  th<“se parts  are  endowed  with; 
whether  they  are  formed  by  a final  depositation,  or  are  still  under  the  influence  of  tlie  circu- 
lating vessels,  whether  they  possess  a principle  of  self-preservation  independent  of  vascularity, 
or  are  like  common  dead  matter  altogether  out  of  the  system. 

The  formation  of  bone  has  been  very  fully  described.  The  formation  of  shell  is  more 
like  that  of  teeth.  The  testaceous  shell  consists  of  layers ; the  layers  are  formed  successive- 
ly by  secretion  from  the  animal  body,  and  each  successive  la}’er  is  broader  than  the  prece- 
ding, answering  to  the  encreased  circumference  of  the  animal.  Reaumeur  broke  the  shell 
of  a snail,  and  he  found  that  when  he  covered  the  surface  of  tlie  creature  and  prevented  the 
exudation,  no  shell  was  formed.  There  has  been  a question  agitated  regarding  the  possibi- 
lity of  nutrition,  without  the  intervention  of  vessels,  which  b^rs  upon  this  subject,  of  the 
nature  of  shell  and  teeth. 


334 


OF  THE  TEETH. 


of  the  matter  forming  the  central  part  of  the  tooth,  and  of  the 
fang=:,  is  similar  to  other  bones  of  the  body  ; but  when  we 
examine  the  hardness  and  the  density  of  the  tooth,  and  see  that 
it  is  not  even  porous,  or  apparently  capable  of  giving  passage 
to  vessels,  we  conclude  that  it  is  not  vascular,  and  are  apt  to 
suppose  that  it  holds  its  connection  with  the  living  jaw-bone  by 
some  other  tenor  than  that  of  vessels,  or  the  circulation  of  the 
blood  through  it.  The  body  and  fangs  of  a tooth  are  cover- 
ed with  a periosteum  like  other  bones.  The  vascularity  of  the 
periosteum,  which  surrounds  the  tooth,  and  the  vessels  which 
enter  by  the  fangs  to  the  cavity  of  the  tooth,  seem  to  be  a pro- 
vision for  supplying  them  plentifully  with  blood  ; but  on  further 
examination,  it  will  prove  to  be  a means  only  of  fixing  the  tooth 
in  the  socket,  and  of  preserving  the  sensibility  of  the  nerve  in 
the  cavity  of  the  tooth.  As  the  bony  part  of  the  tooth  has 
often  been  coloured  by  feeding  young  animals  with  madder,  it 
might  deceive  some  to  suppose  that  there  is  blood  circulating 
through  the  body  of  the  tooth,  and  that  the  tooth  undergoes 
the  same  changes  by  absorption  which  the  other  bones  are  pro- 
ved to  do.  But  these  experiments  may  have  been  made  while 
the  teeth  were  forming  by  a secretion  from  the  pulp,  and  of 
course  they  might  be  coloured  without  the  experiment  affording 
a fair  proof  that  the  circulation  continues  in  the  tooth  after  it  is 
formed. 


OF  THE  VASCULARITY  AND  CONSTITUTION  OF  THE  BONY  PART 
OF  THE  TOOTH. 

The  teeth  undergo  changes  of  colour  in  the  living  body,  to 
which  it  would  appear  they  could  not  be  liable  as  dead  mat- 
ter. They  become  yellow,  transparent,  and  brittle  with  old 
age  ; and  when  a tooth  has  been  knocked  from  its  socket, 
and  replaced,  dentists  have  observed  that  it  loses  its  whiteness, 
and  assumes  a darker  hue. 

The  absorption  of  the  roots  in  consequence  of  the  caries  of 
the  body  of  the  tooth,  and  the  absorption  of  the  fangs  of  the 
deciduous  teeth,  are  further  alleged  in  proof  of  their  vascula- 
rity ; not  only  the  pressure  of  the  rising  tooth  on  the  fangs  of 
the  temporary  teeth  will  cause  an  absorption  of  the  latter,  but 
the  fangs  of  the  temporary  teeth  will  waste  and  be  absorbed,  so 
as  to  drop  out  without  the  mechanical  pressure  of  the  permanent 
teeth,  and  before  they  have  advanced  to  be  in  contact  with  the 
former. 

The  teeth  seem  acutely  sensible ; but  a little  consideration 
teaches  us  that  the  bard  substance  of  the  teeth  is  not  endowed 


OF  THE  TEETH. 


135 


■with  sensibility,  and  that  it  must  be  the  remains  of  the  vascular 
pulp,  presently  to  be  described,  occupying  the  centre  of  tbe 
tooth,  which  being  supplied  with  nerves,  gives  the  acute  pain 
in  tooth-ache.  It  is  as  a medium  communicating  or  abstract- 
ing heat,  that  the  tooth  itself  gives  pain.  When  wu’ought  upon 
by  the  dentist,  no  sensation  is  produced  unless  the  tremor  be 
communicated  to  the  centre,  or  unless  the  abrading,  or  cut- 
ting instruments,  be  so  plied  as  to  heat  the  tooth  then  an 
acute  pain  is  produced  from  the  heat  communicated  to  the 
centre  ; and  so  ice  or  extremely  cold  liquids,  talien  into  the 
mouth,  produce  pain,  from  the  cold  affecting  the  pulp  through 
the  body  of  the  tooth. 

As  living  parts,  the  teeth  have  adhesion  to  the  periosteum, 
and  are  connected  with  their  internal  pulp ; but  when  they 
spoil,  and  are  eroded,  the  disease  spreads  inwardly,  probably 
destroying  the  life  of  the  bony  part  of  the  tooth,  tbe  progress 
of  which  disease  is  marked  by  a change  of  colour  penetrating 
beyond  the  caries  towards  the  centre  of  the  tooth.  When 
this  discolouration  has  reached  the  internal  surface,  the  pain 
of  tooth-ache  is  excited ; the  pulp  vascular,  and  supplied  with 
nerves,  inflames,  from  a want  of  accordance  with  the  altered 
state  of  the  tooth,  just  as  the  dead  surface  of  a bone  will  in- 
flame the  central  periosteum  and  marrow.  The  extreme  pain 
produced  by  this  state  of  the  tooth  probably  proceeds  from 
the  delicate  and  sensible  pulp  swelling  in  the  confinement  of 
the  cavity  of  the  tooth. 

In  caries  of  the  teeth,  the  body  of  the  tooth  is  discoloured 
deep  in  its  substance  long  before  the  pulp  of  the  central  cavity 
is  exposed  by  the  progress  of  the  caries.  No  exfoliation,  or 
exostosis,  takes  place  upon  that  part  of  the  tooth  which  is 
above  the  gum,  which  may  be  owing  to  the  mere  compactness 
of  the  ossific  depositions. 

In  the  further  consideration  of  this  subject,  there  are  circum- 
stances which  will  make  us  conclude  that  there  is  no  vascular 
action  in  the  teeth,  and  incline  us  to  believe  that  they  possess  a 
low  degree  oflife,  independent  of  vascular  action.  Supposing  the 
bony  part  of  the  tooth  to  be  vascular,  and  to  possess  the  princi- 
ple of  life,  is  not  the  firm  adhesion  and  contact  of  the  enamel 
to  the  body  of  the  tooth  a curious  instance  of  a part  destitute  of 
life  adhering  to  the  surface  of  a living  part  without  producing 
the  cornmon  effects  of  excitement  and  exfoliation,  or  inflam- 
mation in  the  latter 

In  rickets,  and  molities  ossium,  and  other  diseases  of  debility 
in  which  the  bone  wastes,  or  the  growth  is  retarded,  the  grown 
teeth  are  not  altered  in  their  form  or  properties.  The  effects 
which  we  perceive  in  the  beny  system  under  these  diseases, 


136 


OF  THE  TEETH. 


are  produced  by  the  activity  of  the  absorbents  prevailing  over 
the  action  of  the  red  vessels;  while  in  the  teeth  no  such  effect 
can  take  place,  if  they  are  formed  by  a deposition  of  bony  mat- 
ter which  is  not  re-absorbed,  nor  subject  to  the  revolution  of 
deposition  and  re-absorption,  which  takes  place  in  other  parts 
of  the  body.  Accordingly,  we  find  in  rickets,  where  the  hard- 
est bone  yields,  where  the  jaw-bone  itself  is  distorted  or  alter- 
ed in  its  form,  that  the  teeth  remain  distinguished  for  their  size 
and  beauty.  In  molities  ossium,  I have  fdhnd  the  teeth  loose, 
but  hard  in  their  substance.  In  rickets  the  teeth  are  large,  and 
perfectly  formed,  while  the  jaws  are  stinted  and  interrupted  in 
their  growth.  The  consequence  of  this  is,  that  the  teeth  form 
a larger  range  than  the  jaw,  and  give  a characteristic  protube- 
rance to  the  mouth. 

I must  here  observe,  however,  that  if  a child  is  in  bad  health 
during  the  formation  of  the  teeth,  they  are  often  deficient  in 
form,  or  in  the  crust  of  enamel  which  covers  them,  instances  of 
which  my  reader  may  see  in  my  Collection. 

When  an  adult  tooth  of  one  jaw  is  lost,  there  appears  to  be 
a growth  of  the  tooth  of  the  opposite  jaw ; but  I believe  the 
tooth  only  projects  from  its  socket  a little  further,  in  conse- 
quence of  the  want  of  that  pressure  to  which  it  is  naturally  ac- 
commodated. The  teeth  of  the  are  wasted  by  attri- 

tion and  seem  to  grow.  This  is  indeed  a growth,  but  it  is  of 
the  nature  of  the  first  formation  of  the  tooth  proceeding  from 
the  pulp.* 

Much  has  been  said  of  balls  being  found  in  elephants’  teeth, 
as  they  are  found  in  bones,  the  bony  matter  accumulated 
around  the  ball,  a proof  of  the  inflammation  of  the  tooth,  and 
of  course  of  its  vascularity.  The  specimens  in  the  collections 
of  Haller,  Blumenbach  and  Monro,  are  quoted.  I possess  a 
great  variety  of  these  specimens,  of  both  iron  and  leaden  balls 
immersed  in  the  ivory  of  the  elephant’s  tusk,  but  they  prove 
that  the  pulp  continuing  to  secrete  bony  matter,  has  envelop- 
ed the  ball  after  it  has  pierced  the  shell  of  the  tooth. 

The  roots  of  the  teeth  are  sometimes  found  enlarged,  dis- 
torted, or  with  exostosis  formed  upon  them.  Again  the  ca- 
vity of  the  tooth  is  found  filled  up  with  what  appears  to  be  new 
matter,  or  around  the  fangs  we  often  find  a small  sac  of  pus, 
which  is  drawn  out  in  extracting  the  tooth.  Nevertheless,  in 
these  examples  of  disease,  there  are  no  unequivocal  marks  of 
vascular  action  in  the  tooth;  the  unusual  form,  or  exostosis  of 
the  routs,  is  produced  by  an  original  defect  in  the  formation. 
The  filling  up  of  the  cavity  of  the  tooth  is  caused  in  the  same 

* Pee  the  ingenious  Inaugural  Dissertation  of  Dr.  Blake. 


OP  THE  TEETH. 


137 


way,  or  by  the  resumed  ossific  action  of  the  pulp,  in  conse- 
quence of  the  disease  and  destruction  of  the  body  of  the  tooth  ; 
and  the  abscesses  which  surround  the  fangs  are  caused  by  the 
death  of  the  tooth,  in  consequence  of  which  it  has  lost  its 
sympathy  with  the  surrounding  living  parts,  and  becomes  a 
source  of  irritation  like  any  other  foreign  body. 

The  transplanting  of  teeth  presents  another  very  interest- 
ing phenomenon.  A tooth  recently  drawn,  and  placed  accu- 
rately into  a socket  from  which  one  has  been  taken,  will  ad- 
here there : nay,  it  will  even  adhere  to  any  living  part,  as  in 
the  comb  of  a cock.  This,  however,  proves  only  that  the 
tooth  possesses  vitality;  for  after  if  is  taken  from  the  natural 
socket,  if  it  be  kept  any  time  it  will  not  adhere ; it  has  become 
a dead  part,  and  the  living  substSnce  refuses  to  unite  with  it. 
Again,  and  in  opposition  to  this,  is  it  not  very  extraordinary 
that  a tooth  may  be  burnt  by  chemical  agents,  or  the  actual 
cautery,  down  to  the  centre,  and  yet  retain  its  hold  ; or  that 
the  body  of  the  tooth  may  be  cut  off,  and  a new  tooth  fixed 
into  it  by  a pivot  Had  the  teeth  any'  vascular  action,  this 
torturing  would  cause  re-action  and  disease  in  them.  Some- 
times the  most  terrible  effects  are  produced  by  these  opera- 
tions, as  tetanus,  abscess  in  the  jaws,  &tc. ; but  this  happens  in 
consequence  of  the  central  nerve  being  bruised  by  the  wedg- 
ing of  the  pivot  in  the  cavity  of  the  tooth,  or  by  the  roots  of 
the  tooth  becoming,  as  dead  bodies,  a source  of  irritation  to 
the  surrounding  sockets. 

Of  the  gums. — The  necks  of  the  teeth  are  surrounded  by 
the  gums,  a red,  vascular,  but  firm  substance,  which  covers 
the  alveolar  processes.  To  the  bone  and  to  the  teeth  the 
gums  adhere  very  strongly,  but  the  edge  touching  the  tooth 
is  loose.  The  gums  have  little  sensibility  in  their  healthy  and 
sound  state ; and  by  mastication,  when  the  teeth  are  lost,  they 
gain  a degree  of  hardness  which  proves  almost  a substitute  for 
the  teeth.  The  use  of  the  gum  is  chiefly  to  give  firmness  to  the 
teeth,  and  at  the  same  time,  to  give  them  that  kind  of  support 
which  breaks  the  jar  or  bony  contact.  Like  the  alveolar  pro- 
cess, the  gums  have  a secret  connection  with  the  state  of  the 
teeth.  Before  the  milk-teeth  appear,  there  is  a firm  ridge 
which  runs  along  the  gums,*  but  this  is  thrown  off,  or  wastes 
with  the  rising  of  the  teeth  : and  as  the  teeth  rise,  the  proper 
gums  grow,  and  embrace  them  firmly.  The  gum  is  firm,  and 
in  close  adhesion,  when  the  teeth  are  healthy  ; loose,  spongy, 
or  shrunk,  when  th(>y  are  diseased.  The  only  means  of  ope- 
rating upon  the  general  state  of  the  teeth  is  through  the  gums; 
and  by  keeping  them  in  a state  of  healthy  aetien,  by  the  brush 

* -See  Herissant. 

s 


VOt.  li 


138 


OF  THE  TEETH. 


and  tinctures,  the  dentist  fixes  the  teeth,  and  preserves  them 
healthy ; but  when  they  are  allowed  to  be  loose  and  spongy, 
and  subject  to  frequent  bleeding,  (which  is  improperly  called 
a scorbutic  state,)  the  teeth  become  loose,  and  the  gums 
painful.  If  a healthy  tooth  be  implanted  in  the  jaw,  the  gum 
grows  up  around  it,  and  adlieres  to  it ; but  if  it  be  dead  or 
diseased,  the  gum  ulcerates,  loosens,  and  shrinks  from  it; 
and  this  shrinking  of  the  gums  is  soon  followed  by  the  absorp- 
tion of  the  socket. 

We  must  conclude,  that  the  whole  of  the  phenomena  dis- 
played in  the  formation,  adhesion,  and  diseases  of  the  teeth, 
show  them  to  be  possessed  of  life,  and  that  they  have  a corres- 
pondence or  sympathy  with  the  surrounding  parts.  But  are 
we  prepared  to  acquiesce  in  the  opinion  of  Mr.  Hunter,  that 
they  possess  vitality  while  yet  they  have  no  vascular  action 
within  them  ? We  naturally  say,  how  can  such  vitality  exist 
independently  of  a circulation  ? But  there  are  not  wanting  ex- 
amples of  an  obscure  and  low  degree  of  life  existing  in  animals' 
ova,  or  seeds,  for  seasons  without  a circulation ; and  if  for 
seasons,  why  not  for  a term  of  life  We  never  observe  the 
animal  economy  providing  superfluously  ; and  since  there  is  no 
instance  to  be  observed  in  which  the  teeth  have  shown  a 
power  of  renovation,  why  should  they  be  possessed  of  vascula- 
rity and  action  to  no  useful  end  ^ All  that  seems  necessary  to 
them  is,  that  they  should  firmly  adhere  without  acting  as  a 
foreign  and  extraneous  body  to  the  surrounding  parts,  and 
this,  vitality,  without  vascular  action,  seems  calculated  te* 
provide. 

OF  THE  FORMATION  AND  GROWTH  OF  THE  TEETH. 

In  the  jaws  of  a child  newly  born,  there  are  contained  two 
sets  of  teeth  as  it  were  in  embryo  : the  deciduous,  temporary, 
or  milk-teeth  ; and  the  permanent  teeth.  The  necessity  for 
this  double  set  of  teeth  evidently  is  to  be  found  in  the  incapa- 
city of  alteration  of  shape  or  size  in  the  teeth,  as  in  other  parts 
of  the  body  ; the  smaller  teeth,  which  rise  first,  and  are  adapt- 
ed to  the  curve  and  size  of  the  jaw-bone  of  an  infant,  require 
to  be  succeeded  by  others,  larger,  stronger,  and  carrying  their 
roots  deeper  in  the  jaw. 

Each  tooth  is  formed  in  a little  sac,  which  lies  betwixt  the 
plates  of  bone  that  form  the  jaw-bone  of  the  foetus,  or  child, 
under  the  vascular  gum,  and  connect  with  it. 

When  we  open  one  of  these  sacs  at  an  early  period  of  the 
formation  of  the  tooth,  a very  curious  appearance  presents 
itself:  a little  shell  of  bone  is  seen  within  the  sac,  but  no  ena- 


OF  THE  TEETH. 


139 


Biel  is  yet  formed.  Upon  raising  the  shell  of  bone,  which  is 
01  the  shape  of  the  tooth,  and  is  the  outer  layer  of  the  bony 
substance  of  the  tooth,  a soft  vascular  stool,  or  pulp,*  is  found 
to  have  been  the  mould  on  which  this  outer  layer  of  ossific 
matter  has  been  formed ; and  a further  observation  will  lead 
us  to  conclude,  that  this  bony  part  of  the  tooth  is  in  the  pro- 
gress of  being  formed  by  successive  layers  of  matter  thrown 
out  from  the  surface  of  this  vascular  pulp ; though  many  have 
explained  the  formation  of  the  tooth,  by  supposing  that  the 
layers  of  this  pulp  were  successively  ossified. 

If  we  now  lurn  our  attention  to  the  state  of  those  teeth  which 
we  know  to  be  later  of  rising  above  the  gum,  we  shall  find  the 
ossification  still  less  advanced,  and  a mere  point,  or  perhaps 
several  points  of  the  deposited  matter  on  the  top  of  the 
pulp. 

The  pulp,  or  vascular  papilla  on  which  the  tooth  is  formed, 
has  not  only  this  peculiar  property  of  ossification,  but,  as  the 
period  of  revolution  advances,  where  it  forms  the  rudiments 
of  the  molares  for  example,  its  base  splits  so  as  to  form  the 
mould  of  two,  three,  or  four  fangs,  or  roots ; for  around  these 
divisions  of  the  pulp  the  ossific  matter  is  thrown  out  so  as  to 
form  a tube,  continued  downwards  from  the  body  of  the  tooth. 
Gradually,  and  by  successive  layers  of  matter  on  the  inside  of 
this  tube,  it  becomes  a strong  root,  or  fang,  and  the  bony 
matter  has  so  encroached  on  the  cavity,  that  only  a small  canal 
remains,  and  the  appearance  of  the  pulp  is  quite  altered, 
having  shrunk  in  this  narrow  space. 

We  have  said  that  the  tooth  forming  on  its  pulp,  or  vascu- 
lar bed,  is  surrounded  with  a membrane  giving  the  whole  the 
appearance  of  a little  sac.  This  membrane  has  also  an  impor- 
tant use.  It  is  vascular  also  as  the  pulp  is,  but  it  is  more  con- 
nected with  the  gums,  and  receives  its  vessels  from  the  sur- 
face, while  the  pulp,  lying  under  the  shell  of  the  tooth,  re- 
ceives its  blood-vessels  from  that  branch  of  the  internal  maxil- 
lary which  takes  its  course  in  the  jaw. 

The  enamel  is  formed  after  the  body  of  the  tooth  has  con- 
siderably advanced  towards  its  perfect  form.  It  is  formed  by 
a secretion  from  the  capsule,  or  membrane,  which  invests  the 
teeth, f and  which  is  originally  continuous  with  the  lower  part 
of  the  pulp.  The  enamel  is  thicker  at  the  point,  and  on  the 
body  of  the  tooth,  than  at  its  neck.  Mr.  Hunter  supposed 
that  the  capsule  always  secreting,  and  the  upper  part  of  the 
tooth  being  formed  first,  it  would  follow,  of  course,  that  the 

* Le  noyau,  la  coqiie,  or  le  germe  de  la  dent,  by  the  French  authors. 

t This  outer  sac  has  been  called  chorion,  from  the  numerous  vessels  distributed  upon  i' 
See  Herissant 


14^ 


©F  THE  TEETH. 


point  and  body  of  the  tooth  would  be  covered  with  a thicker- 
deposition  ; but  it  rather  appears  that  that  part  of  the  sac  op- 
posite to  the  upper  part,  and  body  of  the  tooth,  has  a greater 
power  of  secreting,  being  in  truth  more  vascular  and  spongy; 
for  the  whole  of  the  body  of  the  bony  part  of  the  tooth  is 
formed  before  the  enamel  invests  the  tooth. 

We  are  indebted  to  M.  Herissant  for  much  of  the  explana- 
tion of  the  manner  in  which  the  enamel  is  formed.  He  des- 
cribes the  sac,*  its  attachment  to  the  pulp  and  to  the  neck  of 
the  teeth, — as  the  tooth  advances  to  its  perfect  form,  the  sac 
also  changes.  At  first  it  is  delicate  and  thin,  but  it  thickens 
apace.  And  he  asserts,  that  if  after  this  progress  is  begun  you 
examine  the  inner  surface  of  it  with  a glass,  you  will  perceive 
it  to  be  composed  of  little  vesicles  in  regular  order,  and  which 
sometimes  have  a limpid  fluid  contained  in  them.  This  liquid 
exuded  upon  the  surface  of  the  teeth  he  supposes  to  form  the 
enamel.  He  explains  also  how  this  sac,  originally  investing 
the  body  and  neck  of  the  tooth,  being  pierced  by  the  edge  of 
the  tooth,  and  the  tooth  rising  through  it  is  inverted,  and  by 
still  keeping  its  connection  with  the  circle  of  the  crown  of  the 
tooth,  rises  up  in  connection  with  the  gum,  and  in  some 
degree  forms  the  new  gum  which  surrounds  the  tooth. 

The  sac  which  encloses  the  rudiments  of  the  tooth  consists 
of  a double  membrane.  The  outer  membrane  is  of  a looser 
texture,  and  vascular;  the  inner  is  vascular  also,  but  delicate 
and  soft.  Mr.  Hunter  said,  that  while  the  tooth  is  within  the 
gum,  there  is  always  a mucilaginous  fluid,  like  the  sinovia  in  the 
joints  between  this  membrane  and  the  pulp  of  the  tooth.  I 
do  not  imagine  that  the  enamel  is  produced  by  the  concretion 
of  this  humour,  which  we  may  find  at  any  period  of  the  growth 
of  the  body  of  the  tooth  ; but  that  the  secreting  surface  chan- 
ges the  nature  of  its  action,  when  the  bone  of  the  tooth  is  per- 
fected in  its  outer  layer. 

This  subject  of  the  formation  of  teeth  would  be  incomplete 
if  we  left  unexplained  the  peculiar  structure  of  the  teeth  of 
gramenivorous  animals. 

Mr.  Corse,  in  a curious  paper  in  the  Philosophical  Transac- 
tions of  London  for  the  year  1799,  describes  the  grinding  tooth 
of  an  elephant  in  the  following  terms  : In  describing  the  struc- 
ture of  the  grinders,  it  must  be  observed,  that  a grinder  is 
composed  of  several  distinct  lamina;  or  teeth,  each  covered 
with  its  proper  enamel  ; and  that  these  teeth  are  merely  joined 
to  each  other  by  an  intermediate  softer  substance,  acting  like 
cement. 


* Ressemble  assez  a une  petite  bourse  fermee. 


OF  THE  TEETH. 


141 


The  structure  of  the  grinders,  even  from  the  first  glance, 
must  appear  very  curious,  being  composed  of  a number  of 
perpendicular  laminje,  which  may  be  considered  as  so  many 
teeth,  each  covered  with  a strong  enamel,  and  joined  to  one 
another  by  the  common  osseous  matter  This  being  much 
softer  than  the  enamel,  wears  away  faster,  by  the  mastication 
of  the  food  ; and,  in  a few  months  after  some  of  these  teeth 
cut  the  gum,  the  enamel  remains  considerably  higher,  so  that 
the  surface  of  each  grinder  soon  acquires  a ribbed  appearance, 
as  if  originally  formed  with  ridges. 

The  pulp  of  gramenivorous  animals  is  not  shaped  like  that 
which  forms  the  human  tooth  ; it  consists  of  several  processes 
united  at  their  base.  The  capsule  has  also  processes  which 
hang  into  the  interstices  of  the  pulp  ; the  pulp  forms  a shell 
of  bone  which  in  time  covers  it.  The  processes  of  the  cap- 
sule, which  of  course  hang  into  the  interstices  of  this  layer  of 
bone,  (which  has  taken  the  exact  form  of  the  pulp,)  form  over 
the  bone  layers  of  enamel.  The  tooth  now  consists  of  conical 
processes  of  bone,  united  at  their  roots,  and  the  surfaces  of 
these  processes  have  deposited  on  them  the  enamel.  The 
membranous  productions  of  the  capsule  having  completed  the 
enamel,  change  the  nature  of  their  secretion  somewhat,  and 
throw  out  a bony  matter,  which  Dr.  Blake  has  called  the 
ervsta  petrosa.  By  the  formation  of  this  last  matter  of  the 
tooth  the  processes  which  secrete  are  encroached  upon  so 
much,  that  they  shrink  altogether,  and  into  the  place  left  by 
them  after  they  have  lost  their  power  of  secreting,  foreign 
matter  is  sometimes  introduced  by  mastication.* 

The  effect  of  this  formation  is  to  make  the  layers  of  the 
enamel  pervade  the  whole  substance  of  the  tooth,  the  better 
to  make  it  stand  against  the  continued  attrition  necessary  in 
the  grinding  and  rumination  of  the  herbiverous  and  grameni- 
vorous animals.  The  grinding  teeth  of  the  purely  carnivorous 
animals,  as  of  the  lion  and  tiger,  close  like  the  blades  of  scis- 
sars  : they  are  prevented  by  the  long  canine  teeth  from  mo- 
ving laterally  ; and  as  they  are  not  subject  to  attrition,  the 
enamel  only  covers  their  surfaces. 

OF  THE  GROWTH  OF  THE  SECOND  SET  OF  TEETH,  AND  THE 
SHEDDING  OF  THE  FIRST. 

The  first,  or  deciduous  set  of  teeth,  being  adapted  only  for 

* See  a paper  of  Mr.  Home’s  in  the  Philosophical  Transactions,  and  Dr.  Blake’s  Inaugu 
•al  Dissertation. 


142 


OF  THE  TEETH. 


the  jaws  of  a child,  are  destined  to  be  shed,  and  to  give  place 
to  the  adult,  or  permanent  set  of  teeth.  Accordingly,  in  ob- 
serving tlie  progress  of  the  formation  of  the  first  teeth,  the 
rudiments  of  the  second  may  also  be  seen  in  the  fauus  of  the 
seventh  or  eighth  month  ; and  in  the  fifth  and  sixth  month  af- 
ter birth,  the  ossification  begins  in  them.  The  rudiments  of 
the  permanent  teeth  may  be  observed  even  when  the  sac  is 
very  small,  and  appear  like  a filament  stretching  up  to  the  neck 
of  the  sac  of  the  deciduous  teeth.*  These  sacs  lie  on  the 
inner  side  of  the  jaw-bone,  and  when  further  advanced,  the 
necks  of  the  two  sacs  (both  as  yet  under  the  gum)  are  united ; 
but  when  the  first  teeth  are  fully  formed,  and  have  risen  above 
the  gum,  the  alveolar  processes  have  been  at  the  same  time 
formed  around  them,  and  now  the  sacs  of  the  permanent  teeth 
have  a connection  with  the  gums  through  a small  foramen  in 
the  jaw-bone,  behind  the  space  through  which  the  first  teeth 
have  risen. 

The  opinion  entertained,  that  the  second  set  of  teeth  push 
out  the  first,  is  erroneous,  for  the  change  on  the  deciduous  and 
the  growing  teeth  seems  to  be  influenced  by  laws  of  coincidence, 
indeed,  but  not  of  mechanical  action.  Sometimes  we  observe 
the  falling  tooth  wasted  at  the  root,  or  on  the  side  of  the  fang, 
by  the  pressure  of  the  rising  tooth.  Now  here  we  should  sup- 
pose that  the  newly  formed  tooth  should  be  the  most  apt  to  be 
absorbed  by  the  pressure  of  the  root  of  the  deciduous  tooth, 
did  we  not  recollect  that  the  new  tooth  is  invested  with  the 
hard  enamel,  while  the  pressure  on  the  other  is  upon  the  bony 
root.  But  there  is  more  than  this  necessary  to  the  explanation 
of  the  shedding  of  the  teeth,  for  often  the  fang  is  wasted,  and 
the  tooth  adheres  only  by  the  gum,  and  the  permanent  tooth 
has  made  little  progress  in  its  elevation,  and  has  not  pressed 
upon  it. 

This  decay  and  wasting  of  the  fangs  of  the  teeth  looks 
more  like  a satisf?ictory  proof  of  their  vascularity,  than  any 
other  change  to  which  they  are  subject.  Yet  there  seems  to 
be  no  reason  why  we  should  not  suppose,  that  as  the  rudiments 
of  the  teeth  rise  into  action  at  a particular  time,  and  form  the 
bony  centre  of  the  tooth,  the  decomposition  should  be  effect- 
ed by  similar  laws ; that  at  a particular  period  the  tooth  should 
decay,  and  that  the  decay  of  the  tooth  should  begin  with  the 
destruction  of  the  fangs.  Has  the  bony  part  of  the  tooth  a 
tendency  to  dissolution  independently  of  a circulation  of  blood 
through  it  ^ and  as  the  roots  waste,  do  the  surrounding  vascu- 
lar parts  absorb  its  substance  ^ or,  does  the  surrounding  vascu- 


* See  the  plate  of  the  Teeth. 


OF  TEE  TEETH. 


143 


lar  substance  operate  on  the  tooth  dissolving,  and  absorbing  it, 
as  it  is  said  a dead  bone  is  absorbed,  when  placed  upon  an 
ulcer  ? 

When  the  internal  vascular  substance  of  a tooth  is  destroy- 
ed, it  does  not  waste  : when  teeth  are  pivoted,  tbeir  roots  re- 
main twenty  years  without  wasting  or  being  absorbed ; and 
when  the  vascular  centre  of  the  milk-teeth  is  destroyed,  their 
roots  waste  no  more,  and  they  continue  adhering  to  the  gum. 
This  seems  to  point  to  the  internal  membrane  of  the  tooth  as 
the  means  of  its  absorption. 

It  is  no  proof  of  the  first  set  being  pushed  out  by  the  second 
set  of  teeth,  that  if  the  permanent  teeth  do  not  rise,  the  first 
will  remain,  their  roots  unwasted  and  firm  even  to  old  age  ; for 
still  I contend,  that  there  is  an  agreement  and  coincidence, 
betwixt  the  two  sets  of  teeth  in  their  changes,  and  also  in  the 
alveoli,  by  which  they  are  surrounded ; hut  this  is  not  pro- 
duced by  the  pressure  of  the  rising  teeth.  When  a dentist 
sees  a tooth  seated  out  of  the  proper  line,  and  draws  it,  and 
finds  that  he  has  made  the  mistake  of  extracting  the  adult 
tooth,  letting  the  milk-tooth  remain,  he  must  not  expect  that 
the  milk-tooth  will  keep  its  place,  for  the  contrary  will  hap- 
pen ; it  will  in  general  fall  out. 

The  old  and  the  new  teeth  are  lodged  in  distinct  compart- 
ments of  the  jaw-hone,  and  what  is  more  curious,  their  alveoli  are 
distinct ; for  as  the  roots  of  the  first  teeth  decay,  their  alveolar 
processes  are  absorbed,  while  again,  as  tbe  new  teeth  rise  from 
their  deep  seat  in  the  jaw-bone,  they  are  accompanied  with 
new  alveoli ; and  the  chief  art  of  the  dentist  in  shifting  the 
seat  of  the  teeth,  is  gradually  to  push  them  along  the  jaw,  not- 
withstanding the  hony  partitions  or  alveoli  and  processes,  so 
as  to  bring  them  into  equal  and  seemly  lines.  It  is  curious  to 
observe,  that  the  alveoli  will,  by  the  falling  out  of  one  tooth,  or 
the  operation  of  wedging  betwixt  the  teeth,  change  their  place 
in  the  jaw’. 

When  a tooth  is  lost,  it  appears  as  if  the  space  it  occupied 
were  partly  filled  up  by  an  increased  thickness  of  the  adjacent 
teeth,  and  partly  by  the  lengthening  of  that  which  is  opposite  : 
indeed,  this  appearance  has  been  brought  as  proof  of  the 
continual  growth  of  teeth.  But  there  is  a fallacy  in  the  obser- 
vation ; for  when  the  space  appears  to  have  become  narrow 
by  the  approximation  of  the  two  adjacent  teeth,  it  is  not  owing 
to  any  increase  of  their  breadth,  but  to  their  moving  from  that 
side  where  they  are  well  supported  to  the  other  side  where 
they  are  not.  From  this  reason  they  get  an  inclined  direc- 
tion ; and  this  inclination  may  be  observed  in  several  ef  the 
adjoining  teeth. 


144 


OF  THE  TEETH. 


No  circumstance  can  better  illustrate  how  perfect  the  depen- 
dence of  the  alveoli  is  upon  the  teeth,  than  that  of  their  being 
thrown  off  with  them  in  extensive  exfoliations.  I have  aspecimen 
of  this  in  my  Collection,  where  the  whole  circle  of  the  alveolar 
processes  and  teeth  is  thrown  off.  This  happened  after  the 
confluent  small-pox.  I think  I recollect  a similar  case  occur- 
ring to  Dr.  Blake.  In  those  tumours  which  arise  from  the 
alveoli  and  gums,  filling  the  mouth  with  a cancerous  mass,  and 
softening  the  upper  part  of  the  jaw,  there  is  no  eradicating 
the  disease  but  by  the  taking  away  the  whole  adventitious  part  of 
the  jaw  which  belongs  to  the  teeth,  and  leaving  only  the  firmer 
base.  But  even  this  operation  will  be  too  often  unsuccessful. 


BOOK  II. 

OF  THE  MUSCLES. 


CHAP.  I. 


MUSCLES  OE  THE  FACE,  EYE,  AND  EAR. 


1.  MUSCLES  OF  THE  FACE. 

A HE  occiPiTO  FRONTALIS  is  a broad  and  thin  muscular  ex- 
Dansion,  which  covers  all  the  upper  part  of  the  cranium.  It 
consists  of  two  bellies,  with  an  intermediate  sheet  of  flat  ten- 
don. The  one  belly  covers  the  occiput,  the  other  covers  the 
forehead,  and  the  tendinous  expansion  covers  all  the  upper 
part  of  the  head ; by  which  it  has  happened  that  the  most 
eminent  anatomists,  as  Cowper,  (p.  29.)  have  misnamed  its 
tendon,  pericranium ; many  have  reckoned  it  two  dis- 
tinct muscles,  viz.  the  occipital  and  frontal,  while 
others  (because  of  a sort  of  rapha,  or  line  of  division  in  the 
middle  of  each  belly  ,)  have  described  four  muscles,  viz.  two 
frontal,  and  two  occipital  muscles.  But  it  is  truly  a double- 
bellied  muscle  ; and  the  broad  thin  tendon,  which  belongs 
equally  to  both  bellies,  lies  above  the  true  pericranium,  and 
slides  upon  it.  The  muscle  is  therefore  named,  with  strict 
propriety,  occlpito-frontalis,  sometimes epicranius,  sometimes 

BIVENTER,  or  DIGASTRICUS  CAPITIS. 

Origin. — The  occipital  portion  is  the  fixed  point  of  this 
muscle  arising  from  the  superior  ti’ansverse  ridge  of  the  occi- 
pital bone,  and  covering  the  back  part  of  the  head,  from  the 
mastoid  process  of  one  side,  round  to  that  on  the  opposite  side 
of  the  head.  And  by  the  perpendicular  ridge  of  the  occiput, 
it  is  marked  with  a slight  division  in  the  middle. 

Insertion. — The  fore  belly  of  the  muscle  which  covers  the 
forehead,  is  fixed  more  into  the  skin  and  ey^e-brows  than  into 
the  bone  ; it  is  slightly  attached  to  the  bone,  near  the  inner 
end  of  the  orbitary  ridge,  and  especially  about  the  inner  corner 
of  the  eye,  and  the  root  of  the  nose,  by  a smaller  and  acute 

VOL.  I.  T 


146 


MUSCLES  OF  THE 


pointed  process ; but  still  its  chief  attachment  is  to  the  eye-lids 
and  skin. 

The  TENDON  or  thin  membraneous  expansion  which  joins 
the  two  bellies,  is  exceedingly  thin : it  has  on  its  inner  side 
much  loose  cellular  substance,  by  which,  though  attached  to 
the  true  pericranium,  it  slides  easily  and  smoothly  upon  it  j 
but  its  outer  surface  is  so  firn)ly  attached  to  the  skin,  and  its 
fore  belly  adheres  so  firmly  to  the  eye-brows,  that  it  is  very 
difficult  to  dissect  it  clean  and  fair. 

I consider  the  occipital  belly  as  the  fixed  point,  having  a 
firm  origin  from  the  ridge  of  the  bone;  its  frontal  belly  has 
the  loose  end  attached,  not  to  the  os  frontis,  but  to  the  eye- 
brow and  skin,  and  its  office,  that  of  raising  the  eye-brows, 
wrinkling  tbe  forehead,  and  corrugating  the  whole  of  the  hairy 
scalp,  like  that  muscle  under  the  skins  of  animals,  which  shrinks 
when  they  are  cold  or  rudely  touched,  and  by  which  they 
shake  off  flies  or  insects.  But  it  is  a muscle  more  employed 
in  expressing  passions,  than  in  performing  useful  motions,  and 
it  is  often  so  thin,  as  hardly  to  be  perceived.  In  some  it  is 
entirely  wanting,  and  many  who  have  the  muscle,  have  no 
command  nor  power  over  it. 

There  is  a small,  neat,  and  pointed  slip  of  the  occipito  fron- 
talis, which  goes  down  with  a peak  towards  the  nose,  and  is 
inserted  into  the  small  nasal  bone.  This  process  being  much 
below  the  end  of  the  eye-brow,  must  pull  it  downwards ; so 
that  while  the  great  muscle  raises  the  eye-brow  and  skin  of 
the  forehead,  this  small  nasal  slip  pulls  the  eye-brow  down- 
wards again,  restoring  it  to  its  place,  and  smoothing  the  skin. 
It  may  be  considered  as  the  antagonist  of  the  great  occipital 
and  frontal  bellies,  and  might  almost  be  described  as  a dis- 
tinct muscle.  It  is  so  mingled  with  the  compressor  nasis,  and 
part  of  the  levator  labii  superioris  alae  que  nasi,  that  there  i,s 
some  difficulty  in  dividing  them. 

II.  The  coRRUGAToK  suPERCiLii  is  another  slip  which 
might  be  fairly  enough  referred,  like  this,  to  the  occipital 
muscle ; but  being  in  many  subjects  particularly  strong,  it  is 
best  described  as  distinct.*  The  lower  end  of  the  nasal  slip 
of  the  occipito  frontalis  is  fixed  to  the  nasal  bone.  The  lower 
end  of  the  little  slip,  the  corrugator  supercilii,  is  fixed  into  the 
internal  angular  process  ; and  from  the  inner  angle  of  the  eye, 
the  fibres  sweep  round  the  edge  of  the  orbit,  and  going  ob- 
liquely upwards  and  outwards,  are  so  mixed  with  the  fibres  of 
the  frontal  muscle,  and  of  the  orbicularis  oculi,  where  these 
two  touch  each  other,  that  it  is  doubtful  to  which  of  these 

* It  lies  entirely  under  the  frontal  niujcle : it  is  firmer  and  smoother  in  its  fibres. 


FACE,  EYE,  AND  EAR. 


147 


greater  muscles  this  little  one  might  be  most  properly  referred. 
So  this  slip  of  oblique  fibres,  rising  from  the  inner  angle  of  the 
eye,  and  being  fixed  into  the  eye-brow,  also  antagonizes  the 
occipito  frontalis,  and  drawing  the  eye-brows  together,  and 
wrinkling  the  space  betwixt  them,  is  very  rightly  named  cor- 
RUGATOR  suPERCiLii.  We  frequently  find  a slip  running  from 
the  outer  and  lower  part  of  the  muscle  to  join  the  levator  labii 
superioris  proprius. 

III.  Orbicularis  oculi,  or  palpebrarum,  is  a neat  and 
regular  muscle,  surrounding  the  eye,  and  covering  the  eye-lids 
in  a circular  form.  It  is  exceedingly  flat  and  thin ; is  about  an 
inch  in  breadth ; lies  immediately  under  the  skin  of  the  eye- 
lids, and  is  immediately  attached  to  them,  and  but  little  con- 
nected with  the  bone.  It  has  one  small  tendon  in  the  inner 
corner  of  the  eye,  which  is  both  its  origin  and  insertion  ; for  it 
begins  and  ends  in  it.  This  small  tendon  is  easily  felt  through 
the  skin  in  the  inner  corner  of  the  eye.  It  arises  by  a little 
white  knot  from  the  nasal  process  of  the  upper  jaw-bone.  Its 
fibres  immediately  become  muscular,  and  spread  out  thin  over 
the  upper  eye-lid.  They  pass  over  it  to  the  outer  corner  of 
the  eye,  where  they  cross  a little,  and  having  covered  just  the 
edge  of  the  temple  with  their  tbin  expanded  fibres,  they  re- 
turn in  a circular  form  round  by  the  lower  eye-lid  to  the  point 
from  whence  they  had  set  out.  This  is,  in  all  its  course,  a very 
thin  muscular  expansion,  with  regular  orbicular  fibres.  It  is 
rather  a little  broader  over  the  lower  eye-lid,  extends  itself  a 
little  upon  the  face  beyond  the  brim  of  the  socket,  both  at  the 
temple,  and  upon  the  cheek ; and  its  fibres  cross  each  other  a 
little  at  the  outer  angle ; so  that  some  understanding  this  cross- 
ing as  a meeting  of  fibres  from  the  upper  and  from  the  lower 
muscle,  have  described  it  as  two  semi-circular  muscles.  And 
those  fibres  which  are  next  to  the  tarsus  or  cartilaginous  circle 
of  the  eye-lids,  were  distinguished  by  Riolan,  under  the  title  of 
MUscuLus  ciLiARis.  Oui’  name  expresses  the  common  opi- 
nion, that  it  is  a circular  muscle,  whose  chief  point  or  fulcrum  is 
in  the  inner  corner  of  the  eye,  and  which  serves  as  a sphincter 
for  closing  the  eye.  It  squeezes  with  spasmodic  violence, 
when  the  eye  is  injured,  as  by  dust.  And  by  its  drawing  down 
the  eye-lids  so  firmly,  it  presses  up  the  ball  of  the  eye  hard 
into  the  socket,  and  forces  the  lachrymal  gland  that  is  within 
the  socket,  so  as  to  procure  a flow  of  tears. 

IV.  Levator  palpebre  superioris. — This  small  muscle 
arises  deep  within  the  socket,  from  the  margin  of  that  hole 
which  gives  passage  to  the  optic  nerve.  It  begins  by  a small 
flat  tendon  in  the  bottom  of  the  optic  cavity,  becomes  gradu- 
ally broader  as  it  goes  over  the  eye-hall ; it  ends  in  the  eye- 


148 


MUSCLES  OE  THE 


lid,  by  a broad  expansion  of  muscular  fibres,  which  finally  ter- 
minate in  a short  flat  tendon.  It  lies  under  the  orbicularis  pal- 
pebrae,  is  inserted  into  the  whole  length  of  the  cartilage  of  the 
tarsus,  and  raises  and  opens  the  upper  eye-lid.  And  the  divi- 
sion of  the  orbicularis  oculi  into  two,  by  the  older  anatomists, 
was  a consequence  of  their  not  knowing  of  the  true  levator  pal- 
pebrae,  and  their  not  being  able  to  describe  any  muscle  by 
which  the  upper  eye-lid  could  be  raised,  except  the  upper 
half  of  the  orbicularis. 

The  occipito  frontalis,  but  especially  its  occipital  belly, 
raises  the  eye-brows ; the  pointed  slip  of  the  same  muscle  pulls 
them  downwards;  the  corrugator  pulls  them  directly  inwards, 
and  knits  the  brows;  the  levator  palpebras  opens  the  eye-lid 
and  the  orbicularis  oculi  closes  the  eye.  Whether  certain 
fibres  from  the  platysma-myoides,  (a  thin  flat  muscle  which 
mounts  from  the  neck  over  the  cheek,)  may  not  pull  down  the 
lower  eye-lid,  or  whether  some  straggling  fibi’es,  arising  from 
the  zygoma,  may  not  have  the  appearance  of  a depressor  of 
the  lower  eye-lid,  it  is  not  necessary  to  determine,  since  there 
is  no  regularly  appointed  muscle,  and  the  lower  eye-lid  is 
almost  immoveable,  at  least  in  man. 


MUSCLES  OF  THE  NOSE  AND  MOUTH. 

V.  Levator  labh  superioris  and  al®  nasi.  Cowper 
describes  the  levator  labii  superioris  as  an  irregular  production 
of  the  frontalis,  extending  along  the  nostrils.  But  it  is  a neat 
and  delicate  muscle,  which  arises,  by  a small  double  tendon, 
from  the  nasal  process  of  the  upper  jaw-bone,  close  by  the  ten- 
don of  the  orbicularis  oculi.  It  is  one  little  fasciculis  of  mus- 
cular fibres  above  ; but  as  it  approaches  the  nose,  it  spreads  out 
broader,  dividing  into  two  small  fasciculi,  one  of  which  is  im- 
planted into  the  wing  or  cartilage  of  the  nose,  and  the  other 
passing  the  angle  of  the  nose,  goes  to  the  upper  lip  : thus  it  is 
pyramidal  with  its  base  downwards,  and  was  named  pyramida- 
lis  by  Casserius,  Winslow,  and  others.  It  is  called  by  Cowper 
dilator  al*  nasi ; it  raises  the  upper  lip,  and  spreads  the  nostrils 
Avide,  as  is  observed  in  a paroxysm  of  rage,  or  in  asthmatics. 

VI.  The  levator  labii  superioris  proprius  is  distinguish- 
ed by  the  name  of  levator  proprius,  because  there  are  two 
others ; one  belonging  to  the  angle  of  the  mouth,  and  conse- 
quently to  both  lips ; and  one  common  to  the  lip  and  nostril. 

The  levator  proprius  is  often  named  musculus  incisivus,  be- 
cause it  arises  from  the  upper  jaw,  just  above  the  incisores,  or 
cutting  teeth,  and  consequently  just  under  tbe  edge  of  the 


FACE,  EYE,  AND  EAR.  14i> 

orbit : it  is  broad  at  its  origin  ; it  lies  flat  and  runs  downwards, 
and  obliquely  inwards,  to  the  middle  of  the  lip  till  it  meets  its 
fellow  just  in  the  filtrum.*  It  pulls  the  upper  lip  and  the  sep- 
tum of  the  nose  directly  upwards.  It  generally  receives  a slip 
from  the  orbicularis  oculi. 

VII.  The  LEVATOR  ANGULI  ORIS,  is  Called  alsO  LEVATOR 
COMMUNIS  LABiORUM,  because  it  operates  equally  on  both  lips. 

It  is  named  caninus  ; for  as  the  last  named  muscle  rises  from 
the  upper  jaw-bone  above  the  incisores  or  cutting  teeth,  this 
arises  above  the  canini  or  dog-teeth,  or  above  the  first  grinder, 
by  a very  short  double  tendon.  The  exact  place  of  its  origin 
is  half  way  betwixt  the  first  grinder  and  the  infra  orbitary  hole  : 
it  is  mixed  with  the  orbicularis  oris,  at  the  corner  of  the  mouth, 
so  that  it  raises  the  angle  of  the  mouth  upwards. 

VIII.  The  zYGOMATicus  MAJOR  has  nearly  the  same  direc- 
tion and  use  with  this  one  : for  it  arises  from  the  cheek-bone 
near  the  zygomatic  suture ; runs  downwards  and  inwards  to  the 
corner  of  the  mouth  ; is  a long  and  slender  muscle,  which  ends 
by  mixing  its  fibres  with  the  orbicularis  oris  and  the  depressor 
of  the  lip. 

IX.  The  ZYGOMATICUS  MINOR  ai'ises  a little  higher  upon  the 
cheek-bone,  but  nearer  the  nose  ; it  is  much  slenderer  than 
the  last,  and  is  often  wanting.  In  negroes  we  frequently  find 
three  zygomatic  muscles. 

It  is  the  zygomatic  muscle  that  marks  the  face  with  that 
line  which  extends  from  the  cheek-bone  to  the  corner  of  the 
mouth,  and  which  is  so  strong  in  many.  The  zygomatic  mus- 
cles pull  the  angles  of  the  mouth  upwards  as  in  laughter ; or 
one  of  them  distorts  the  mouth,  whence  the  zygomatic  muscle 
has  got  the  name  of  distortor  oris ; the  strong  action  of  the 
muscle  is  particularly  seen  in  laughter,  rage,  grinning. 

X.  Buccinator.  The  buccinator  was  long  thought  to  be 
a muscle  of  the  lower  jaw,  arising  from  the  upper  alveoli,  and 
inserted  into  the  lower  alveoli  to  pull  the  jaw  upwards ; but  its 
origin  and  insertion,  and  the  direction  of  its  fibres,  are  quite 
the  reverse  of  this.  For  this  large  flat  muscle,  which  forms, 
in  a manner,  the  walls  of  the  cheek,  ai’ises  chiefly  from  the 
coronoid  process  of  the  lower  jaw-hone  and  partly  also  from 
the  end  of  the  alveoli  or  socket  process  of  the  upper  jaw,  close 
by  the  pterygoid  process  of  the  sphenoid  bone ; it  arises  also 
from  the  upper  jaw ; it  goes  forwards  with  direct  fibres  to  be 
implanted  into  the  corner  of  the  mouth  ; it  is  thin  and  flat, 
and  forms  the  walls  of  the  cheek  ; it  is  perforated  in  the  mid- 
dle of  the  cheek  by  the  duct  of  the  parotid  gland.  Albinus 

^ Thp  filtrum  is  thp  siipprficial  gutter  along  the  upper  lip  from  tho  partition  of  tlie  nose  to 
■ he  tip  of  the  lip. 


150 


MUSCLES  OP  THE 


describes  two  irregular  sets  of  fibres  besides  mentioning  those 
which  are  running  directly  to  the  angle  of  the  mouth  : 1 . One 

narrow  slip  which  runs  in  a semi-circular  direction  and  joins  the 
inner  surface  of  the  upper  lip.  2.  Another  considerable  slip 
which  runs  much  in  the  direction  of  the  orbicularis  towards 
the  middle  of  the  lip,  this  he  calls  the  appendix  of  the  buccina- 
tor. These  are  its  principal  uses;  that  it  flattens  the  cheek, 
and  so  assists  in  swallowing  liquids ; that  it  turns,  or  helps  to 
turn,  the  morsel  in  the  mouth  while  chewing,  and  prevents  its 
getting  without  the  line  of  the  teeth : in  blowing  wind  instru- 
ments, it  both  receives  and  expels  the  wind : it  dilates  like  a 
bag,vso  as  to  receive  the  wind  in  the  cheeks  ; and  it  contracts 
upon  the  wind  so  as  to  expel  the  wind,  and  to  swell  the  note  : 
In  blowing  the  strong  wind  instruments,  we  cannot  blow  from 
the  lungs,  for  it  stresses  the  breathing,  but  reserve  the  air  in  the 
mouth,  which  we  keep  continually  full ; and  from  this  it  is 
named,  from  blowing  the  trumpet,  the  buccinator. 

XI.  Dbpressor  ANGULi  ORIS. — The  depressor  anguli  oris  is 
a neat  small  triangular  muscle,  and  is  indeed  very  commonly 
named  musculus  triangularis  labiorum,  from  its  shape. 
The  base  of  the  triangle  is  at  the  line  of  the  lower  jaw,  where 
the  muscle  rises  with  a flat  fleshy  head  about  an  inch  in  breadth. 
It  grows  smaller  gradually  as  it  rises  towards  the  corner  of  the 
mouth,  where  it  is  implanted,  small  almost  in  a point,  and 
directly  opposite  to  the  zygomatic  and  levator  muscles  ; and 
as  the  zygomatic  muscle  makes  a line  from  the  cheek  down  to 
the  angle  of  the  mouth,  this  makes  a line  from  the  chin  up  to 
the  corner  of  the  mouth.  It  is  chiefly  active  in  expressing  the 
passions,  and  gives  form  to  the  chin  and  mouth.  In  cheerful 
motions,  as  laughter,  smiling,  &lc.  the  zygomatics  and  levators 
pull  the  angles  of  the  mouth  upwards.  In  fear,  hatred,  re- 
venge, contempt,  and  the  angry  passions,  the  ti’iangulares  pull 
the  corners  of  the  mouth  downwards  ; and  at  the  place  w'here 
these  meet,  there  is  formed  a sort  of  rising  at  the  angle  of  the 
mouth : for  a great  many  tendons  are  crowded  into  this  one 
point ; the  zygomatic,  levator,  depressor,  and  orbicularis  oris 
muscles  meeting  and  crossing  each  other  at  this  place. 

XII.  The  oEPREssoR  LABii  iNEERiORis  is  a Small  muscle, 
the  discovery  which  Cowper  claims  for  himself.  It  is  a small 
muscle,  lying  on  each  side  of  the  chin,  which,  with  its  fellow, 
resembles  very  much  the  levators  of  the  upper  lip.  The  de- 
pressor labii  inferioris  arises  on  each  side  of  the  chin,  from  the 
lower  jaw-bone,  under  the  line  of  the  triangular  muscle.  It 
grows  obliquely  upwards  and  inwards,  till  it  meets  its  fellow  in 
the  middle  of  the  lip  ; and  where  the  muscles  of  the  opposite 
side  meet,  there  is  a little  filtrum  or  furrow  on  the  lower  lip,  as 


151 


FACE,  EYE,  AND  EAR. 

ou  the  upper  one.  It  mixes  its  fibres  with  the-orbicularls,  and 
its  use  is  to  pull  the  lip  downwards ; each  muscle  is  of  a square 
form,  and  thence  has  been  often  named  quadratus  gena;,  the 
square  muscle  of  the  chin. 

XIII.  The  OKBicuEARis  ORIS,  or  muscle  round  the  mouth, 
is  often  named  constrictor  oris,  sphincter,  or  osculator. 
It  is  very  regular;  it  is  an  inch  in  breadth,  and  constitutes  the 
thickness  of  the  lips  : it  lies  in  the  red  part  of  the  lips,  and  is  of 
a circular  form,  surrounding  the  mouth  after  the  same  manner 
that  the  orbicularis  oculi  encircles  the  eye.  We  see  a degree 
of  crossing  in  the  fibres  at  the  angles  of  the  mouth,  whence  it 
has  been  considered  by  many  not  as  a circular  muscle,  but  as 
one  consisting  of  two  semi-circular  muscles,  the  semi  orbicu- 
laris SUPERIOR,  and  semi  orbicularis  inferior.  Its  fixed 
points  are  the  two  angles  of  the  mouth  ; at  that  swelling  which 
is  formed  by  the  union  of  the  zygomatic,  triangular,  and  other 
muscles,  part  of  it  takes  origin  from  the  alveolar  process  of  the 
canine  teeth.  The  chief  use  of  this  muscle  is  to  contract  the 
mouth,  and  antagonize  the  other  muscles  which  I have  just  de- 
scribed. Often  a small  slip  runs  up  from  the  middle  of  the  up- 
per lip,  to  the  tip  of  the  nose  ; it  is  the  nasalis  labii  superio- 
Ris  of  Albinus ; it  lies  exactly  in  the  furrow  of  the  filtrum,  and 
is  occasionally  a levator  of  the  upper  lip,  or  a depressor  of  the 
tip  of  the  nose. 

These  muscles  of  the  nose  and  lips  are  not  useful  merely  in 
expressing  the  passions ; that  is  but  a secondary  and  accidental 
use,  while  their  great  office  is  to  perform  those  continual  move- 
ments, which  breathing,  speaking,  chewing,  swallowing,  require. 
There  are  muscles  for  opening  the  mouth  in  various  directions, 
which  are  all  antagonized  by  this  one,  the  orbicularis  oris. 
The  levator  labii  superioris,  and  the  depressor  labii  inferioris, 
separate  the  lips  and  open  the  mouth.  The  levator  anguli  oris, 
along  with  the  zygomatic  muscles,  raises  the  cheek,  and  dilates 
the  corners  of  the  mouth.  The  buccinator  pulls  the  corner  of 
the  mouth  directly  backwards,  opening  the  mouth.  The  an- 
gularis  oris  also  dilates  the  mouth,  pulls  the  angles  of  the  mouth 
downwards  and  backwards,  and  forms  it  into  a circle,  if  the 
others  act  at  the  same  time;  but  the  orbicularis  oris  is  the  largest 
and  strongest,  (formed  as  it  were,  by  the  fibres  of  all  these 
taking  a new  direction,  and  turning  round  the  lips,)  shuts  the 
mouth,  and  antagonizes  them  all,  and  from  an  opening  as  wide 
as  the  mouth  can  require,  shuts  the  mouth  at  pleasure,  so 
closely,  as  to  retain  the  very  breath  against  all  the  force  of  the 
lungs.  It  is  the  true  antagonist  of  all  the  other  muscles,  and 
they  and  the  orbicularis  mutually  re-act  on  each  other,  in 
alternately  opening  and  closing  the.  month.  This  phenome- 


152 


MUSCLES  OE  THE 


non  of  the  orbicularis  muscle,  dilating  to  such  a wideness,  and 
in  an  instant  closing  the  mouth  again,  with  such  perfect  accura-  ij 
cy,  as  to  retain  the  breath,  puts  to  nought  all  the  vain  calcula-  | 
tions  about  the  contraction  of  muscles,  as  that  they  can  con-  | 

tract  no  more  than  one  third  of  their  length ; for  here  is  an  |) 

infinite  contraction,  such  as  no  process  can  measure.  It  is  a “ 

paralysis  of  these  muscles  that  so  often  occasions  a hideous  | 

distortion  of  the  face ; for  when  the  one  side  of  the  body  falls  < 

into  palsy,  the  muscles  of  one  cheek  cease  to  act ; the  mus-  ^ 

cles  of  the  other  cheek  continue  to  act  with  their  usual  degree  j 

of  power.  This  contraction  of  the  muscles  of  one  cheek  ex- 
cites also  the  orbicularis  oris  to  act,  and  so  tbe  mouth  is  pursed 
up,  and  the  lips  and  angles  of  the  mouth  are  drawn  towards 
one  side. 

There  are  some  smaller  muscles,  which,  lying  under  these, 
could  not  be  described  without  danger  of  confusion;  as — 

XIV.  The  UKPRESSOR  labii  suPERiORis  and  alje  nasi, 

which  is  very  small,  and  lies  concealed  under  the  other  mus-  j 

cles.  It  rises  from  the  gum  or  socket  of  the  fore  teeth,  and  > 

thence  is  named,  by  Winslow,  incisivus  medius.  It  goes  into 
the  root  of  the  nostril,  and  pulls  it,  and,  of  course,  the  upper 

lip  down,  and  is  named,  by  Albinus,  depressor  alae  nasi. 

XV.  The  CONSTRICTOR  NASI,  or  compressor  of  the  nose,  is 

a small  scattered  bundle  of  muscular  fibres,  which  crosses  the  | 
wings,  and  goes  to  the  very  point  of  the  nose ; for  one  arises 
from  the  wing  of  the  nose  on  each  side,  and  meets  its  fellow  j 
in  the  middle  ridge,  where  both  are  fixed  into  the  middle  car- 
tilage, or  into  the  lower  point  of  the  nasal  bones,  meeting  with  | 

the  peak  of  the  frontal  muscle,  or  its  scattered  fibres.  But  this  | 

muscle  is  so  difficultly  found,  that  when  Cowper  saw  it  dis-  ' 

tinctly  marked  in  Bidloe’s  12th  table,  be  considered  it  as  a 
fiction,  having  sought  for  it  very  carefully,  but  in  vain,  ]l| 

And  XVI.  The  LEVATOR  MENTi,  which  arises  from  the  lower  ni 
jaw,  at  the  root  of  the  cutting  tooth,  has  been  named  incisi- 
vus INFERIOR.  It  is  inserted  into  the  skin,  on  the  very  centre 
of  the  chin  : by  its  contraction  it  draws  the  centre  of  the  chin 
into  a dimple  ; and  from  its  moving  the  under  lip  at  the  same 
time,  it  is  named  levator  labii  inferiores. 

MUSCLES  OF  THE  EXTERNAL  EAR. 

Though  perhaps  not  one  of  ten  thousand  has  the  power  of 
moving  the  outward  ear,  yet  there  are  many  thin  and  scattered 
fibres  of  muscles  about  the  root  of  the  cartilage  of  the  ear,  to 
which  we  cannot  refuse  the  name  and  distinction  of  muscles ; 


FACE,  EYE,  AND  EAR. 


las 

and  which  serve,  indeed,  to  indicate,  that  nature  had  intended 
a degree  of  motion,  which,  perhaps  by  the  manner  of  covering 
the  heads  of  children,  we  may  have  lost.  But  in  a few,  these 
fasciculi  of  fibres,  have  not  the  form  only,  but  the  uses  of  mus- 
cles. The  celebrated  Mr.  Mery,  was  wont,  when  lecturing  on 
this  subject,  to  amuse  his  pupils,  saying,  pleasantly,  “ that  in 
one  thing,  he  surely  belonged  to  the  long  ear’d  tribe  upon 
which  he  moved  his  ears  very  rapidly  backwards  and  forwards.* 

XVII.  SuPEKioR  AURis  is  named  attollens  because  it  lifts 
the  ear  upwards : it  is  a very  thin,  flat  expansion,  which  can 
hardly  be  distinguished  from  the  fascia  of  the  temporal  mus- 
cle, upon  which  it  lies ; it  arises  broad  and  circular,  from  the 
expanded  tendon  of  the  occipito  frontalis,  and  is  inserted  into 
the  back  part  of  the  antihelix. 

XVIII.  Anterior  aukis  is  a very  delicate,  thin,  and  nar- 
row expansion,  arising  about  the  zygoma,  or  rather  from  the 
fascia,  with  which  the  zygoma  is  covered ; it  is  inserted  by  a 
tendon  into  that  eminence  of  the  helix  which  divides  the 
concha. 

XIX.  The  POSTERIOR  ATjRis  is  also  a small  muscle,  very  de- 
licate and  thin ; but  the  anterior  rises  in  one  small  and  narrow 
slip  only,  while  this,  the  posterior,  rises  commonly,  in  three 
narrow  and  distinct  slips,  from  about  the  place  of  the  mastoid 
process  whence  it  is  often  named  triceps  auris-  These 
fibres  are  often  described  as  two  distinct  muscles,  retrahentes  : 
it  goes  directly  forwards  to  be  inserted  into  the  back  part  of 
the  concha,  opposite  the  septum  that  divides  the  concha,  by 
two  slips. 

But  there  are  still  other  muscles  enumerated,  which  are  not 
for  moving  the  outward  ear  upon  the  head,  but  for  moving,  or 
rather  giving  tension  to  the  cartilages  of  the  outward  ear. 
Those  fibres,  are  merely  muscular  membranes,  which  have 
none  of  the  marks  nor  offices  of  true  muscles  ; they  have  sel- 
dom fleshy  fibres,  and  the  parts  upon  which  they  lie  are  fixed. 
Heister  denies  them  the  title  of  muscles,  and  calls  them  mus- 
eular  membranes  only. 

The  ring  and  other  bendings  of  the  outward  ear  are  called 
helix  and  antihelix,  tragus  and  antitragus  ; and  this  determines 
the  names  of  these  ambiguous  fibres,  which  are  sometimes 
found  lying  upon  these  circles  of  the  outward  cartilage,  just 
under  the  skin. 

XX.  The  MuscuLus  helicis  major  lies  upon  the  upper,  or 
sharp  point  of  the  helix  or  outward  ring  ; rising  from  the  upper 

Vide  PaKn,  who  was  his  pupil.  The  celebrated  Albinus  could  move  has  ears. 

f Fibrae  oameae  transverse,  a nobis  descriptse.  Vaisalya. 

VOL.  I..  U 


164 


MUSCLES  OP  THE 


and  acute  point  of  the  helix,  and  inserted  into  the  same  carti" 
lage  a little  above  the  tragus. 

XXL  Helicis  MiNOK  rises  lower  than  the  former,  upon  the 
forepart  of  the  helix,  and  runs  across  the  notch  wiiich  is  in 
that  part  of  the  helix  that  projects  into  the  concha,  the  muscle 
having  its  origin  above  the  notch,  and  its  insertion  below  it. 

XXII.  The  TRAGicus  lying  upon  the  concha,  and  stretching 
to  the  tragus;  takes  its  origin  from  the  middle  of  the  concha 
to  the  root  of  the  tragus,  and  is  inserted  into  the  tip  of  the 
tragus. 

XXIII.  The  ANTiTKAOicus  Hes  OH  the  antitragus,  running 
up  from  this  cartilage  to  be  inserted  into  the  edge  of  the 
concha,  at  the  notch  on  the  termination  of  the  helix. 

XXIV.  And,  lastly.  There  is  the  transvkrsus  aukis  of 
Albinus,  which  runs  in  scattered  fibres  on  the  back  part  of  the 
ear  from  the  prominent  part  of  the  concha  to  the  outer  side  of 
the  antihelix. 


MUSCLES  OF  THE  EYE-BALL. 

The  eye-ball  is  entirely  surrounded  by  muscles,  which  turc 
it  in  all  directions.  There  is  one  muscle  on  either  side,  one 
above  and  one  below  ; these  arise  from  the  very  bottom  of  the 
socket,  spread  out  upon  the  ball  of  the  eye,  and  are  implanted 
into  its  forepart,  where  the  expansions  of  their  colourless  ten- 
dons form  what  is  called  the  white  of  the  eye.  Now  these 
four  muscles,  coming  in  a straight  course  from  the  optic  fora- 
men to  the  anterior  part  of  the  eye-ball,  are  called  the  recti, 
or  straight  muscles  : for  their  pulling  is  from  the  bottom  of  the 
socket.  But  there  are  two  other  muscles  which  are  named 
the  oblique  muscles,  because  they  pull  from  the  edges  of  the 
socket,  and  turn  the  eye  obliquely  ; for  they  go  in  a direction 
exactly  opposite  to  the  recti.  The  recti  come  directly  forwards, 
from  the  bottom  of  the  orbit ; these  go  obliquely  backwards, 
from  the  edge  of  the  orbit;  one  rises  from  the  lower  edge  of 
the  socket,  and  goes  backwards  under  the  eye-ball ; the  other 
rises,  indeed,  along  with  the  recti,  in  the  bottom  of  the  socket, 
but  it  has  a cartilaginous  pulley  on  the  very  edge  of  the  socket, 
at  its  upper  part ; and  its  small  round  tendon  first  runs  through 
this  pulley,  and  then  turns  down  upon  the  eye,  and  goes  back- 
wards; so  that  the  straight  muscles  press  down  the  eye-ball 
deep  into  the  socket,  while  the  oblique  muscles  bring  the  eye- 
ball forwards,  pulling  it  outwards  from  the  socket. 

The  truest  description  of  the  recti  is  as  of  one  muscle,  since 
their  only  variety  is  that  dilference  of  place,  which  is  expres- 


FACE,  EYE,  AND  EAR. 


156 


aed  by  tbe  name  of  each.  They  all  agree  in  these  chief  cir- 
cnmstances,  that  they  arise  by  flat,  but  small  tendons,  round 
the  margin  of  the  optic  hole,  arising  from  the  circle  of  that 
hole,  or  rather  from  the  periosteum  there ; and  there  being 
one  above,  one  below,  and  one  on  eitheir  side,  they  com- 
pletely suiroundthe  optic  nerve,  and  adhere  to  it.  They  are 
neat  and  delicate  muscles,  which  gradually  expand  each  into  a 
fleshy  belly,  which  surrounds  and  covers  the  middle  of  the  ball 
of  tbe  eye.  They  still  go  on  expanding, till  they  at  last  terminate, 
each  in  a broad,  flat,  and  very  white  tendon,  which  covers 
all  the  forepart  of  the  eye,  up  to  tbe  circle  of  the  lucid  cor- 
nea or  w’indow  ; and  their  white  and  shining  tendons  form  that 
enamelled-like  part,  which  lies  without  the  coloured  circle, 
and  which  is  named  the  white  of  the  eye,  or  the  tunica  al- 
buginea, as  if  it  were  absolutely  a distinct  coat, 

Now,  the  only  difference  in  these  straight  muscles  is  in  res- 
pect to  length  5 for  the  optic  nerve  enters  tbe  eye,  not  regu- 
larly in  the  centre,  but  a little  towards  the  inner  side,  so  that 
tbe  rectus  internus,  or  muscle  nearest  the  nose,  is  a little  shorter, 
The  rectus  externus,  or  muscle  nearest  to  the  temple,  is  a little 
longer : but  the  rectus  superior  and  the  rectus  inferior  are  of 
equal  length.  The  uses  of  these  muscles  are  exceedingly  plain. 

XXV.  The  RECTUS  superior,  lifting  the  eye  directly  up- 
wards, is  named  the  musculus  attollens,  tbe  levator  ocu- 
Li  or  SUPER3US,  as  expressive  of  haughtiness  and  pride, 

XXVI.  And  the  rectus  inferior,  which  is  directly  op- 
posite to  it,  is  named  oeprimens  oculi  or  humilis,  as  ex- 
pressing modesty  and  submission. 

XXVII.  The  rectus  internus  is  called  adducens,  as  car- 
rying the  eye  towards  the  nose,  or  bibitorius,  because  it  di- 
rects the  eye  to  the  cup. 

And  XXVIII.  the  rectus  externus,  the  outer  straight  mus- 
cle, as  it  turns  the  eye  from  the  nose,  is  named  abductor  oculi, 
or  ivDiGNABUNDUs,  expressing  anger  or  scorn.  Such  is  the 
effect  of  these  muscles,  that  when  they  act  in  succession,  they 
roll  the  eye  ; but  if  they  act  all  at  once,  the  power  of  each  is 
balanced  by  the  action  of  its  opposite  muscle,  and  tbe  eye  is 
imraoveably  fixed.  So  that  sometimes  in  our  operations, 
when  the  couching  needle  approaches  the  eye,  fear  comes 
upon  the  patient,  and  the  eye  is  fixed  by  a convulsive  action, 
more  firmly  than  it  could  be  by  the  instruments,  or  by  the  fin- 
ger ; so  that  the  speculum  oculi  is  after  such  an  accident  of  no 
use.  The  eye  continues  fixed  during  all  the  operation,  but  it 
is  fixed  in  a most  dangerous  wa}',  by  a power  which  we  cannot 
controul,  and  which  sometimes,  when  our  operation  is  for 
extracting  one  of  the  humours  only,  squeezes  out  the  whole. 


166 


MUSCLES  OF  THE 


XXIX.  The  GBLiquus  SUPF.RIOK  arises  along  with  the  rectf 
in  the  bottom  of  the  eye,  above  and  towards  the  inner  side, 
directing  its  long  tendon  towards  the  inner  angle  of  the  eye; 
and  there  it  passes  its  tendon  through  that  pulley,  whose  hol- 
low I have  marked  in  describing  the  os  frontis,  as  under  the  su- 
perciliary ridge,  and  near  to  the  inner  corner  of  the  eye.  It 
arises  by  a small  tendon  like  one  of  the  recti ; it  goes  over  the 
tipper  part  of  the  eye-ball,  a long  and  slender  muscle,  whence 
it  is  often  named  longissimus  oculi,  the  longest  muscle  of 
the  eye.  It  forms  a small  smooth  round  tendon,  which  passes 
through  the  ring  of  the  cartilaginous  pulley,  which  is  in  the 
margin  of  the  socket.  The  pulley  is  above  the  eye,  and  pro- 
jects farther  than  the  most  prominent  part  of  the  eye-ball,  so 
that  the  tendon  returns  at  an  acute  angle,  and  bends  down- 
wards before  it  can  touch  the  eye-ball.  And  it  not  only  re- 
turns backwards  in  a direction  opposite  to  the  recti  muscles, 
but  it  slips  Bat  under  the  body  of  the  rectus  superior,  and  is 
spread  out  under  it  upon  the  middle  or  behind  the  middle  of 
the  eye,  viz.  about  half  way  betwixt  the  insertion  of  the  rectus, 
and  the  entrance  of  the  optic  nerve. 

XXX.  The  OBLiQ,uus  inferior  is,  with  equal  propriety, 
named  the  musculus  brevissimus  oculi.  It  is  directly  oposite 
to  the  obliquus  superior,  in  form,  place,  office,  &ic.  ; for  it 
arises  from  the  orbitary  process  of  the  superior  maxillary  bone, 
near  its  union  with  the  os  unguis : it  is  short,  flat,  and  broad, 
with  a strong  fleshy  belly  : it  goes  obliquely  backwards  and 
outwards,  lying  under  the  ball  of  the  eye ; and  it  is  inserted 
broad  and  flat  into  the  ball,  exactly  opposite  to  the  insertion 
of  the  obliquus  superior  muscle. 

These  two  muscles  roll  the  eye,  whence  they  are  named 
musculi  circumagentes,  or  amatorii.  But  they  have  still  an- 
other important  office,  viz.  supporting  the  eye  ball,  for  the 
operation  of  its  straight  muscles  ; for  when  the  obliqui  act,  they 
pull  the  eye  forwards,  the  straight  muscles  resist,  and  the  in- 
sertion of  the  oblique  muscles  at  the  middle  of  the  eye-ball 
becomes,  as  it  were,  a fixed  point,  a centre  or  axis  round 
which  the  eye-ball  turns  under  the  operation  of  the  recti  mus- 
cles. The  conjoined  effect  of  the  oblique  muscles  is  to  bring 
the  eye-ball  forwards  from  the  socket,  as  in  straining  the  eye 
to  see  at  some  distant  point.  The  particular  effect  of  the  up- 
per oblique  muscle  is  not  to  bring  the  eye  forward,  but  to  roll 
the  eye  so  as  to  turn  the  pupil  downwards,  and  towards  the 
nose.  And  the  particular  effect  of  the  lower  oblique  muscle 
is  to  reverse  this  action,  to  turn  the  eye  again  upon  its  axis, 
and  to  direct  the  pupil  upwards  and  outwards ; but  the  succes- 
sive actions  of  all  these  muscles  move  the  eye  in  circles,  with 


LOWER  JAW,  THROAT,  AND  TONGUE. 


157 


gradations  so  exquisitely  small,  and  with  such  curious  combi 
nations  as  cannot  be  explained  by  words. 


CHAP.  II. 

MUSCLES  OF  THE  LOWER  JAW,  THROAT,  AND  TONGUE. 

MUSCLES  OF  THE  LOWER  JAW. 

The  lower  jaw  requires  muscles  of  great  power  to  grind  the 
food  ; and  accordingly  it  is  pulled  upwards  by  the  strong  tem- 
poral, masseter,  and  pterygoid  muscles ; but  in  moving  dowm- 
wards,  the  jaw  almost  falls  by  its  own  weight,  and  having 
little  resistance  to  overcome,  any  regular  appointment  of  mus- 
cles for  pulling  down  the  jaw  is  so  little  needed,  that  it  is  pul- 
led downwards  by  muscles  of  such  ambiguous  office,  that  they 
are  equally  employed  in  raising  the  throat,  or  pulling  down 
the  jaw,  so  that  we  hardly  can  determine  to  which  they  be- 
long; for  the  chief  muscles  of  the  throat,  coming  from  the 
lower  jaw,  must,  when  the  jaw  is  fixed,  pull  up  the  throat,  or 
when  the  throat  is  fixed,  depress  the  jaw. 

XXXI.  The  TEMPORAL  MUSCLE  is  the  great  muscle  of  the 
jaw.  It  arises  from  all  the  flat  side  of  the  parietal  bone,  and 
from  the  sphenoid,  temporal,  and  frontal  bones,  in  that  hol- 
low behind  the  eye,  where  they  meet  to  form  the  squamous 
suture.  It  arises  also  from  the  inner  surface  of  that  strong 
tendinous  membrane  which  is  extended  from  the  jugum  to 
the  semi-circular  ridge  of  the  parietal  bone.  The  fibres  are 
bundled  together  and  pressed  into  a small  compass,  so  that  they 
may  pass  under  the  jugum  : there  they  take  a new  hold  upon 
the  inner  surface  of  the  jugum  : the  muscle  is  of  course  pyra- 
midal, its  rays  converging  towards  the  jugum ; its  muscular 
fibres  are  intermixed  with  strong  tendinous  ones ; it  is  particu- 
larly tendinous,  where  it  passes  under  the  jugum;  and  it  has 
both  strength  and  protection  from  that  tendinous  plate  which 
covers  it  in  the  temple.  Its  insertion  is  into  the  coronoid  pro- 
cess of  the  lower  jaw-bone ; not  merely  into  the  tip  of  the 
horn,  but  embracing  it  all  round,  and  down  the  whole  length 
of  the  process,  so  as  to  take  the  firmest  hold. 

XXXII.  The  MASSETER  is  a short,  thick,  and  fleshy  muscle, 
which  gives  the  rounding  of  the  cheek  at  its  back  part.  It 
arises  from  the  upper  jaw-bone,  at  the  back  of  the  antrum,  and 


168 


MUSCLES  OF  THE 


under  the  cheek-bone,  and  from  the  lower  edge  of  the  zygoma. 

It  lies  upon  the  outside  of  the  coronoid  process,  covering  the 
the  branch  of  the  lower  jaw  quite  down  to  its  angle.  It  is 
particularly  strong,  has  many  massy  bundles  of  flesh,  inter- 
spersed with  tendinous  strings ; the  parotid  gland  lies  on  its 
upper  part,  and  the  duct  of  the  gland  (as  it  crosses  the  cheek) 
lies  over  this  muscle.  The  jaw  is  very  firmly  pulled  up  by 
these  two,  which  are  its  most  powerful  muscles  ; and  when  we  • 
bite,  we  can  feel  the  temporal  muscle  swelling  on  the  flat  part 
of  the  temple,  and  this  the  rnasseter  upon  the  back  part  of  the 
cheek. 

XXXIII.  XXXIV.  The  two  pterygoid  muscles  (of  which 
there  are  four  in  all,  two  on  either  side,)  are  named  from  their 
origin  in  the  pterygoid  processes  of  the  sphenoid  bone.  The 
I'TEHYGoiDEUs  iNTERNUs  is  that  One  which  rises  from  the  in- 
ternal or  flatter  pterygoid  process,  and  which  goes  downwards 
and  outwards  to  the  angle  of  the  jaw  on  its  inside;  it  fills  up  the 
fossa  pterygoidea.  I'he  pterygoid eus  externus  arises  from 
the  external  pterygoid  process,  and  goes  not  downwards,  but 
almost  directly  outwards,  and  is  implanted  high  in  the  jaw- 
bone, just  under  its  neck,  and  connected  with  its  capsular  liga- 
ment. Now  the  pterygoideus  internus  descending  to  be  fixed 
to  the  angle  of  the  jaw,  is  longer  and  bigger,  and  is  named 
PTERYGOIDEUS  MAJOR.  The  external  one  going  directly  across, 
and  rather  backwards,  has  less  space  to  traverse,  is  shorter,  and 
is  named  PTERYCoiDEtrs  minor. 

The  jaw  is  moved  chiefly  by  these  muscles;  the  temporalis 
acting  upon  the  coronoid  process  like  a lever,  the  rnasseter 
acting  upon  the  angle,  and  before  it,  and  the  pterygoideus  in- 
ternus balancing  it  within,  like  an  internal  rnasseter  fixed  on 
the  inside  of  the  angle.  All  these  pull  strongly  upwards  for 
biting,  holding,  and  tearing  with  the  teeth  ; and  the  external 
or  lesser  pterygoid  muscle  going  from  witbin  outwards,  pulls 
the  jaw  from  side  to  side,  and  performs  the  motion  of  grind- 
ing. 

muscles  of  THE  THE  THROAT  AND  TONGUE. 

The  muscles  of  the  throat  and  tongue  cannot  be  under- 
stood without  a previous  acquaintance  with  certain  cartilages 
and  bones,  which  form  the  basis  of  the  throat  and  tongue,  and 
the  centre  of  those  motions  which  we  have  next  to  describe. 

The  os  HYOiDES  is  a small  bone  resembling  in  shape  at  least 
the  lower  jaw-bone.  It  has  a middle  thicker  part,  named  its 
basis,  which  is  easily  felt  outwardly  ; it  corresponds  in  place 
with  the  chin,  and  during  life  it  is  distinguished  about  an  inch 


LOWER  JAW,  THROAT,  AND  TONGUE.  159 

below  the  chin,  the  uppermost  of  the  hard  points  which  are 
felt  in  the  forepart  of  the  throat.  Next,  it  has  two  long  horn- 
like processes,  which  go  backwards  along  the  sides  of  the 
throat,  called  the  cornua,  or  horns  of  the  os  hyoides,  and  which 
are  tied  by  a long  ligament  to  the  styloid  process  of  the  tetnpo- 
ral  bone.  And,  lastly,  it  has  small  cartilaginous  pieces  or  join- 
ings, by  which  the  horns  are  united  to  the  basis;  and  often  in 
the  adult  this  joining  is  converted  into  bone.  At  this  point, 
where  the  two  horns  go  backwards,  like  the  legs  of  the  letter 
U,  there  are  commonly,  at  the  gristly  part  of  the  os  hyoides, 
two  small  perpendicular  processes  which  stand  up  from  the 
joining  of  the  horns  to  the  body,  and  these  are  named  the 
appendices  of  the  os  hyoides  or  the  lesser  cornua. 

Now,  this  os  hyoides  forms  by  its  basis  the  root  of  the  tongue, 
thence  it  is  often  named  the  bone  of  the  tongue.  It  forms  at 
the  same  time  a part  of  the  larynx,  which  is  the  collection  of 
cartilages  forming  the  top  of  the  trachea,  or  windpipe  ; and  it 
carries  upon  it  that  cartilage  named  epiglottis,  which,  like  a 
valve,  prevents  any  thing  getting  down  into  the  windpipe.  Its 
horns  extend  along  the  sides  of  the  throat,  keeping  the  open- 
ings of  the  windpipe  and  gullet  extended,  as  we  would  keep  a 
bag  extended  by  two  fingers.  The  chief  muscles  of  the  tongue 
and  of  the  windpipe  arise  from  its  body  ; the  chief  muscles  of 
the  gullet  arise  from  its  horns,  and  especially  from  their  points ; 
it  receives  the  chief  muscles  which  either  raise  or  depress  the 
throat ; and  it  is  the  point  d’appui,  or  fulcrum  for  all  the  mus- 
cles of  the  throat  and  tongue,  and  the  centre  of  all  their  motions. 
It  is  the  centre  of  the  motions  of  the  tongue,  for  it  is  the  origin  of 
these  muscles  which  compose  chiefly  the  bulk  of  the  tongue  ; 
of  the  motions  of  the  trachea  or  windpipe,  for  it  forms  at  once 
the  top  of  the  windpipe,  and  the  root  of  the  tongue,  and  joins 
them  together;  of  the  motions  of  the  pharynx  or  gullet,  for  its 
horns  surround  the  upper  part  of  the  gullet,  and  join  it  to  the 
windpipe;  and  it  forms  the  centre  for  all  the  motions  of  the 
throat  in  general : for  muscles  come  down  from  the  chin  to 
the  os  hyoides,  to  move  the  whole  throat  upwards ; others 
come  up  from  the  sternum,  to  move  the  throat  downwards  ; 
others  come  obliquely  from  the  coracoid  process  of  the  scapu- 
la, to  move  the  throat  backwards,  while  the  os  hyoides  still 
continues  the  centre  of  all  these  motions. 

The  TRACHEA,  or  WINDPIPE,  is  that  tube  which  conveys  the 
air  to  the  lungs ; and  the  larynx  is  the  head  or  figured  part  of 
that  tube  w'hich  is  formed  like  a flute  for  the  modulation  of  the 
voice,  and  consists  of  cartilages,  that  it  may  stand  firm  and  un- 
compressed, either  by  the  passage  of  the  food  or  by  the  weight 
of  the  outward  air ; and  that  it  might  resist  the  contraction  of 


160 


MUSCLES  OF  TME 


the  surrounding  parts,  serving  as  a fulci’um  for  them  in  the  mo- 
tions of  the  jaw,  tongue,  and  gullet.  Its  cartilages  are  first,  the 
■ scuTiFORM,  or  THYROID  Cartilage,  which  is  named  from  its  re- 
semblance to  a shield,  or  rather  it  is  like  the  flood-gates,  or 
folding-doors  of  a canal,  the  meeting  of  the  two  sides  being  in 
the  middle  line  of  the  throat.  This  prominent  line  of  the  thy- 
roid cartilage  is  easily  felt  in  the  middle  of  the  throat,  is  about 
an  inch  in  length,  and  makes  that  tumour  which  is  called  the 
pomum  Adami.  The  flat  sides  of  the  thyroid  cartilage  form 
the  sides  of  the  flute-part  of  the  trachea.  And  there  are  two 
long  horns  at  its  two  upper  corners,  which  rise  like  hooks  above 
the  line  of  the  cartilage,  and  are  joined  to  the  horns  of  the  os 
hyoides,  and  two  similar  but  shorter  hooks  below,  by  which  it 
embraces  the  cricoid  cartilage. 

The  CRICOID  CARTILAGE  is  next  to  the  thyroid,  and  below 
it;  it  is  named  from  its  resemblance  to  a ring  : It  is  indeed 
like  a ring  or  hoop,  but  it  is  not  a hoop  equally  deep  in  all  its 
parts,  it  is  shallow  before;  where  it  ekes  out  the  length  of  the 
thyroid  cartilage,  and  is  deeper  behind,  where  it  forms  the 
back  of  this  flute-like  top  of  the  trachea  ; it  is  the  top  ring  of 
the  trachea,  and  the  lower  ring  of  the  larynx  or  flute-part  of  the 
w'ind-pipe.  And  upon  its  back,  or  deeper  part,  are  seated 
those  two  small  cartilages,  which,  with  their  ligaments,  form 
the  opening  for  the  breath. 

The  ARYTENOID  CARTILAGES  ale  two  Small  triangular  bodies, 
seated  within  the  proteciton  of  the  thyroid  cartilage.  They 
are  foolishly  described  with  cornua  ridges  and  surfaces,  when 
they  are  so  small  that  nothing  further  can  be  observed  of  their 
forms,  than  thaf  they  are  somewhat  conical ; that  the  base  or 
broad  part  of  each  sits  down  upon  the  upper  edge  of  the  cri- 
coid cartilage  at  its  back;  that  the  point  of  each  stands  direct- 
ly upwards,  and  is  a very  little  crooked,  or  hook-like ; that 
standing,  as  they  do,  a little  apart  from  each  other,  they  form 
together  an  opening  something  like  the  spout  of  a ewer,  or 
strouped  bason,  whence  their  names.  And  these  cartilages 
being  covered  with  the  common  membrane  of  the  throat, 
w'hich  is  thick,  and  full  of  mucous  glands,  the  opening  gets  a 
regular  appearance  with  rounded  lips.  From  these  cartilages 
to  the  back  part  of  the  thyroid  cartilages,  ligaments  are  extend- 
ed ; over  these  ligaments  the  lining  membrane  of  the  larynx 
is  laid,  and  betwdxt  the  arytenoid  ligaments  is  formed  the  chink 
or  rima  glottidis ; viz.  the  opening  of  the  wind-pipe.  The 
voice  is,  in  a considerable  degree,  formed  by  the  motion  of 
these  cartilages  and  their  ligaments;  and  the  action  of  the  mus- 
cles of  the  arytenoid  cartilages  are  so  exquisitely  minute,  that 
for  every  changing  of  the  note  (and  there  are  some  thousand 


LOWER  JAW,  THROAT,  AND  TONGUE.  161 

gradations  in  the  compass  of  the  voice)  they  move  in  a propor- 
tioned degree. 

The  EPIGLOTTIS  is  a fifth  cartilage  of  the  trachea,  belonging 
to  it  both  by  connection  and  by  office.  It  is  a broad  triangular 
cartilage,  not  so  hard  as  the  others,  very  elastic,  and  so  exactly 
like  an  artichoke  leaf,  that  no  other  figure  can  represent  it  so 
well.  Its  office  is  to  defend  the  opening  of  the  glottis.  It  is 
fixed  at  once  to  the  os  hyoides,  to  the  thyroid  cartilage,  and  to 
the  root  of  the  tongue,  an^  it  hangs  obliquely  backwards  over 
the  opening  of  the  rima,  or  chink  of  the  glottis  ; it  is  suspend- 
ed by  little  peaks  of  the  membrane,  which  we  call  ligaments 
of  the  glottis,  and  it  is  said  to  be  raised  or  depressed  by  mus- 
cles, which  yet  are  not  very  fairly  described.  But  the  rolling 
of  the  morsel  which  is  swallowed,  and  the  motion  of  the  tongue, 
are  suflicient  to  lay  it  flat  over  the  rima,  so  that  it  is  a perfect 
guard  upon  the  wind-pipe. 

Then  this  is  the  constitution  of  the  larynx.  It  is  of  hard 
cartilages  to  resist  compression,  and  of  a flute  form  at  its  ope- 
ning, to  regulate  the  voice.  The  thyroid  cartilage  is  the 
great  one,  the  chief  defence  before,  and  which  has  edges 
slanting  far  backwards,  to  defend  the  opening  of  the  larynx. 
The  CKicoiD  cartilage,  which  forms  the  upper  ring  of  the  tra- 
chea, supports  the  arytenoid  cartilages,  and  by  its  deepness  be- 
hind, raises  them  so  that  the  opening  of  the  glottis  is  behind 
the  middle  of  the  great  thyroid  cartilage,  and  in  the  deepest 
part  of  it,  well  defended  by  its  projecting  wings.  The  ary- 
tenoid cartilages  form  the  rima  glottidis,  the  chink  by  which 
we  breathe  ; which  as  it  is  narrower  or  wider,  modulates  and 
tunes  the  voice ; the  opening  of  which  is  so  exquisitely  moved 
by  its  muscles  in  singing,  widening  or  contracting  in  most  deli- 
cate degrees,  and  which  is  so  spasmodically  shut  by  the  same 
muscles  when  it  is  touched  by  a drop  of  water,  or  by  a crumb 
of  bread  ; but  the  valve  of  the  glottis,  the  epiglottis  stand- 
ing over  it,  flaps  down  like  the  key  of  a wind  instrument,  so 
that  the  rareness  of  such  accidents  is  wonderful,  when  we  con- 
sider that  the  least  attempt  to  draw  the  breath,  while  we  are 
swallowing,  will  produce  the  accident. 

The  muscles  which  move  the  tongue  and  throat  must  be  far 
too  complicated  to  be  explained  at  all,  without  some  previous 
knowledge  of  these  parts ; and  still,  I fear,  not  easily  to  be  ex- 
plained with  every  help  of  regularity  and  order. 

muscles  op  the  throat. 

By  this  arrangement,  I mean  to  include  under  one  class,  all 
those  muscles  which  move  the  os  hyoides,  or  the  larynx,  and 

VQL.  I.  X 


162 


MUSCLES  OF  THE 


through  these,  as  centrical  points,  move  the  jaws,  gullet,  and 
tongue,  and  which,  though  they  are  inserted  into  the  larynx, 
have  more  relation  to  swallowing,  or  the  motions  of  the  gullet, 
than  to  breathing,  or  to  the  motions  of  the  wind -pipe. 

The  muscles  which  pull  the  throat  down  are  these  : 

XXXIV.  The  sTEKNO-HYOiDRUs,  which  passes  from  the 
sternum  to  the  os  hyoides  ; a flat,  broad,  ribband-like  muscle, 
arises  from  the  upper  piece  of  the  sternum,  rather  within  the 
breast,  and  partly  also  from  the  clavicle  and  cartilage  of  the  first 
rib,  goes  flat  and  smooth  along  the  forepart  of  the  throat, 
mounts  nearly  of  the  same  breadth  to  the  os  hyoides,  and  is 
implanted  into  its  basis,  or  that  part  (which  in  resembling  the 
os  hyoides  to  the  jaw)  we  should  compare  with  the  chin. 

XXXV.  The  STEKNO-THYROIDEUS,  w'liich  passes  in  like 
manner  from  the  sternum  to  the  thyroid  cartilage,  is  like  the 
last,  a flat,  smooth,  ribband-like  muscle,  rather  thicker  and 
more  fleshy,  but  very  uniform  in  its  thickness.  As  the  thyroid 
cartilage  is  below  the  os  hyoides,  the  sterno-thyroid  muscle 
must  lie  under  the  sterno-byoideus  muscle.  It  arises  under 
the  sterno-byoideus  muscle  from  the  sternum  and  cartilage  of 
the  rib,  and  is  implanted  into  the  rough  line-of  the  lower  edge 
of  the  thyroid  cartilage,  and  a little  to  one  side,  but  not  so  much 
as  is  represented  in  Cowper’s  drawings.  It  immediately  co- 
vers the  thyroid  gland,  and  the  operation  of  bronchotomy  is 
sometimes  performed  by  piercing  the  wind-pipe  betwixt  these 
two  muscles. 

XXXVI.  The  OMo-HYOiDEUs,  which-was  once  named  cora- 
co-HYOiDEUs,  being  thought  to  arise  from  the  coracoid  process, 
is  a muscle  of  great  length,  and  very  slender;  reaches  from  the 
shoulder  to  the  os  hyoides ; it  is  like  these  last  mentioned,  a 
long,  flat,  strap-like  muscle,  as  flat  and  as  fleshy,  but  not  so 
broad  as  either  of  the  former.  It  lies  along  the  side  of  the 
neck  ; is  pinched  in  a little  in  the  middle,  where  it  is  divided 
by  a tendinous  cross  line,  which  separates  the  fleshy  belly  into 
two  heads,  whence  it  has  frequently  the  name  of  digastricus 
inferior.  It  arises  from  the  upper  edge  of  the  scapula,  near  its 
notch,  and  is  implanted  into  the  side  of  the  os  hyoides,  where 
the  born  goes  off  from  the  body  of  the  bone. 

These  three  muscles  pull  down  the  throat.  The  sterno-hy- 
oides,  and  sterno-thyroideus  pull  it  directly  downwards  : one 
of  the  omo-hyoidei  acting,  pulls  it  to  one  side  but  if  both  act, 
they  assist  in  pulling  directly  down,  and  brace  the  trachea  at 
the  same  time  a little  down  to  the  back. 

The  muscles  which  move  the  throat  upward  are  : 

XXXVII.  The  MYXo-HYoiDEUs,  a flat  and  broad  muscle, 
which  arises  from  the  whole  semi-circle  of  the  lower  jaw,  {i.  c.) 


LOWER  JAW,  THROAT,  AND  TONGUE.  163 

from  the  backmost  grinders  to  the  point  of  the  chin.  It  rises 
from  the  inner  surface  of  the  jaw-bone,  goes  down  to  the  basis 
of  the  os  hyoides,  proceeds  with  very  regular,  straight,  distinct, 
and  orderly  fibres,  from  the  jaw  to  the  os  hyoides,  is  plainly 
divided  in  the  middle  from  the  symphysis  of  the  jaw  to  the 
middle  of  the  os  hyoides,  by  a middle  tendinous  and  white 
line.  And  though  Cowper  denies  the  authority  of  Vesalius, 
who  divides  it  thus,  it  is  plainly  two  distinct  muscles,  one  be- 
longing to  either  side. 

XXXVIII.  The  GENio-HYOiDEUs  is  a small  neat  pair  of 
muscles  arising  from  the  chin  at  a rough  point,  which  is  easily 
distinguished  within  the  circle  of  the  jaw.  The  mylo-hyoideus 
is  named  from  the  whole  jaw.  The  genio-hyoideus  is  named 
from  the  chin,  arising  from  a small  tubercle  behind  the  chin ; 
its  beginning  is  exceedingly  narrow : as  it  proceeds  downwards, 
it  grows  flat  and  broad  ; it  is  implanted  into  the  basis  of  the  os 
hyoides,  by  a broad  edge,  and  is  a beautiful  and  radiated  mus- 
cle. The  sub-  maxillary  gland  lies  flat  betwixt  this  muscle  and 
the  last,  and  in  the  middle  the  sub-maxillary  duct  pierces  the 
membrane  of  the  mouth,  to  open  under  the  root  of  the  tongue. 
The  two  muscles  move  the  os  hyoides  forwards  and  upwards 
.when  the  jaw  is  fixed  ; but  when  the  os  hyoides  is  fixed  by  the 
muscles  coming  from  the  sternum,  these  muscles  of  the  os 
hyoides  pull  down  the  jaw. 

XXXIX.  The  STVLO-HYOiDEUs  is  one  of  three  beautiful  and 
slender  muscles,  which  come  from  round  the  styloid  process, 
which  all  begin  and  end  with  slender  tendons,  and  with  small 
fleshy  bellies  ; and  one  going  to  the  pharynx  or  gullet,  another 
to  the  os  hyoides,  and  a third  to  the  tongue,  they  coincide  in 
one  common  action  of  drawing  back  the  tongue,  and  pulling 
the  throat  upwards. 

This  one,  the  stylo-hyoideus,  arises  from  about  the  middle 
of  the  styloid  process,  and  going  obliquely  downwards  and  for- 
wards, is  fixed  into  the  side  of  the  os  hyoides,  where,  the  basis 
and  horn  are  joined.  Above  its  insertion,  its  fibres  are  split, 
so  as  to  make  a neat  small  loop,  through  which  the  tendon  of 
the  digastric  muscle  runs.  This  stylo-hyoideus  is  sometimes 
accompanied  with  another  small  fleshy  muscle  like  it,  and  of 
the  same  name,  which  was  first,  perhaps,  observed  by  Cowper, 
and  has  been  named  by  Innes,  stylo-hyoideus  alter;  but  it 
is  not  regular,  nor  has  it  ever  been  acknowledged  as  a distinct 
muscle. 

XL.  The  DIGASTRICUS  Or  BIVENTER  MAXILLiE  INEERIORIS 

muscle,  is  named  from  its  having  two  bellies.  One  belly  arises 
from  a rugged  notch  along  the  root  of  the  mastoid  process, 
where  the  flesh  is  thick  and  strong ; going  obliquely  forwards 


164 


MUSCLES  OF  THE 


and  downwards,  it  forms  along  slender  tendon,  which  passes  by 
the  side  of  the  os  hyoides ; and  as  it  passes,  it  first  slips  through 
the  loop  or  noose  of  the  stylo-hyoideus,  and  then  is  fixed  by 
a tendinous  bridle  to  the  side  of  the  os  hyoides ; and  then  turn- 
ing upwards  towards  the  chin,  it  ends  in  a second  fleshy  belly, 
which,  like  the  first,  is  flat  and  of  a pyramidal  shape,  lying 
above  the  mylo-hyoideus. 

Though  this  muscle  is  often  called  biventer  maxillae  inferio- 
ris,  as  belonging  to  the  lower  jaw,  perhaps  it  does  more  regu- 
larly belong  to  the  throat.  No  doubt,  when  the  os  hyoides  is 
fixed  by  its  own  muscles,  from  the  shoulder  and  sternum,  the 
digastricus  must  act  on  the  jaw ; an  office  which  we  cannot 
doubt,  since  we  often  feel  it  taking  a sudden  spasm,  pulling 
down  the  chin  with  severe  pain,  and  distortion  of  the  neck. 
But  its  chief  office  is  raising  the  os  hyoides;  for  when  the  jaw 
is  fixed,  as  in  swallowing,  the  os  hyoides  pulls  up  the  throat; 
and  this  is  the  true  meaning  of  its  passing  through  the  noose 
of  the  stylo-hyoideus,  and  of  its  connection  with  the  side  of 
the  os  hyoides.  Then  the  digastric  and  stylo-hyoideus  mus- 
cles pull  the  throat  upwards  and  backwards. 

The  muscles  which  move  the  parts  of  the  larynx  upon  each 
other  are  much  smaller,  and  many  of  them  very  minute. 

XLI.  The  HYo-THYKOiOEus  goes  down,  fleshy  and  short, 
from  the  os  hyoides  to  the  thyroid  cartilage.  It  arises  from 
the  lower  border  of  the  thyroid  cartilage  where  the  sterno-thy- 
roideus  terminates,  and  goes  up  along  the  side  of  the  thyroid 
cartilage,  like  a continuation  of  the  sterno-thyroideus  muscle. 
It  passes  the  upper  border  of  the  thyroid  cartilage,  and  is  fixed 
to  the  lower  edge  of  the  os  hyoides,  along  both  its  base  and 
part  of  its  horn. 

XLII.  The  CKico  tiiyhoioeus  is  a very  short  muscle,  pass- 
ing from  the  upper  edge  of  the  cricoid  to  the  lower  margin  of 
the  thyroid  cartilage,  chiefly  at  its  side,  and  partly  attached  to 
its  lower  horn,  which  comes  dow'n  clasping  the  side  of  the 
CRICOID  ring,  so  that  it  is  broader  above,  and  a little  pointed 
below. 

These  two  small  muscles  must  have  their  use,  and  they 
bring  the  thyroid  cartilage  nearer  to  the  os  hyoides,  and  the 
cricoid  nearer  to  the  thyroid  cartilage  ; and  by  thus  shortening 
the  trachea,  or  compressing  it  slightly,  they  may  perhaps  af- 
fect the  voice  ; but  the  muscles  on  which  the  voice  chiefly  de- 
pends are  those  of  the  kima  glottidis  ; for  there  are  many 
small  muscles  which  have  their  attachment  to  the  arytenoid 
cartilages,  and  which  by  their  operation  on  the  tbyro-aryte- 
noid  ligament  govern  the  rima  glottidisj. 


LOWER  JAW,  THROAT,  AND  TONGUE. 


165 


XLIIL  The  MUscuLus  aiiytenoideus  transversus,  is  that 
delicate  muscle  which  contracts  the  glottis  by  drawing  the 
arytenoid  cartilages  towards  each  other.  It  lies  across,  betwixt 
them  at  their  back  part ; it  arises  from  nearly  the  whole  length 
of  one  arytenoid  cartilage  to  go  across,  and  be  inserted  into 
the  same  extent  of  the  opposite  one. 

XLIV.  Arttenoidetjs  obliq,uus  is  one  which  crosses  in  a 
more  oblique  direction,  arising  at  the  root  of  each  arytenoid 
cartilage,  and  going  obliquely  upwards  to  the  point  of  the  op- 
posite one.  These  two  muscles  draw  the  arytenoid  cartilages 
together,  and  close  the  kima  : frequently  we  find  only  one 
oblique  muscle. 

XLV.  The  CRico-ARYTENOiDEUs  POSTICUS,  is  a small  py- 
ramidal muscle,  which  arises  broader  from  the  back  part  of 
the  cricoid  cartilage,  where  the  ring  is  broad  and  deep ; and 
going  directly  upwards,  is  implanted  with  a.  narrow  point,  into 
the  back  of  the  arytenoid  cartilage.  This  pair  of  muscles 
pulls  the  arytenoid  cartilages  directly  backwards,  and  lengthens 
the  slit  of  the  glottis  : perhaps  they  assist  the  former,  in  closing 
it  more  neatly  and  in  producing  more  delicate  modulations  of 
the  voice. 

XJjVI.  The  CRICO-ARYTENOIDEUS  oBLiquus  is  one  w’hich 
comes  from  the  sides  of  the  cricoid  cartilage,  where  it  lies 
under  the  wing  of  the  thyroid,  and  being  implanted  into  the 
sides  of  the  arytenoid  cartilages,  near  their  roots,  must  pull 
these  cartilages  asunder,  and  (as  the  origin  in  the  cricoid  lies 
rather  before  their  insertion  in  the  arytenoid  cartilages)  it  must 
also  slacken  the  lips  of  the  slit ; for  the  lips  of  the  slit  are 
formed  by  two  cords,  which  go  within  the  covering  membrane, 
from  the  tip  of  each  cartilage,  to  the  back  of  the  thyroid  car- 
tilage, and  the  crico-arytenoideus  posticus  must  stretch  these 
cords,  and  the  crico-arytenoideus  lateralis  must  relax  them. 

XLVII.  The  THYREO  ARYTENOiDEUs  is  a muscle  very  like 
the  last  one,  and  assists  it.  It  arises  not  from  the  cricoid  car- 
tilage, but  from  the  back  surface  of  the  wing  of  the  thyroid, 
from  the  hollow  of  its  wing,  or  where  it  covers  the  cricoid ; is 
implanted  into  the  forepart  of  the  arytenoid  cartilage,  and  by 
pulling  the  cartilage  forward  and  sideways,  directly  slackens 
the  ligaments',  and  widens  the  glottis.* 

* There  is  in  Alhinus,  a second  set  of  fibres,  which  he  calls  thyreo  ar5’tenoideus  alter, 
arising  from  the  inner  and  upper  part  of  the  tliyroid  cartilage,  and  inserted  into  the  arytenoid 
cartilage  just  above  the  in-ertion  of  the  crico-arytenoideus  obliqtms ; this  muscle  must  have 
much  the  same  action  as  the  other. 

There  is  another  muscle  which  has  been  omitted  in  the  te.\t,  thyreo  epiglottideus.  It  is 
composed  of  a number  of  fibres,  which  run  from  the  concavity  of  the  thyroid  cartilage  to  the 
side  of  the  epiglottis ; it  has  been  divided  by  Alhinus  into  major  and  minor,  but  this  we  cannot 
expect  to  find  always,  as  it  is  onlv  in  very  muscular  bodies  thn't  we  see  fibres  running  from 


166 


MUSCLES  OP  THE 


These  are  all  the  muscles  which  belong  to  the  larynx ; and 
in  our  arrangement  the  muscles  of  the  palate  and  pharynx 
come  next  in  order. 

When  a morsel  is  to  be  thrown  down  into  the  oesophagus,  or 
tube  which  leads  to  the  stomach,  the  velum  palati,  or  cur- 
tain of  the  palate,  is  drawn  upwards;  the  opening  of  the  throat 
is  dilated  ; the  morsel  is  received  ; then  the  curtain  of  the  pa- 
late falls  down  again.  The  arch  of  the  throat  is  contracted, 
the  bag  of  the  pharynx  is  compressed  by  its  own  muscles ; and 
the  food  is  forced  downwards  into  the  stomach. 

XLVIII.  The  azygosuvuljU.—  ( he  velum  PENmmuM  palati 
is  that  pendulous  curtain  which  we  see  hanging  in  the  back 
part  of  the  mouth,  in  a line  with  the  side  circles  of  the  throat: 
and  the  uvula  is  a small  pap,  or  point  of  flesh,  in  the  centre  of 
that  curtain.  The  azygos  uvul/e,  or  single  muscle  of  the 
uvula,  is  a small  slip  of  straight  fibres,  which  goes  directly 
down  to  the  uvula  in  the  centre  of  the  curtain.  It  arises  from 
the  peak,  or  backmost  sharp  point  of  the  palate  bones,  and 
pulls  the  uvula,  or  pap  of  the  throat  directly  upwards,  re- 
moving it  out  of  the  way  of  the  morsel  which  is  to  pass. 

XLIX.  Levator  palati  mollis  arises  from  the  point  of  the 
os  petrosuin,  and  from  the  Eustachian  tube,  and  also  from 
the  sphenoid  bone.*  These  parts  hang  over  the  roof  of  the 
velum,  and  are  much  higher  than  it ; so  this  muscle  descends 
to  the  velum,  and  spreads  out  in  it ; and  its  office  is  to  pull  up 
the  velum,  to  remove  it  from  being  in  the  way  of  the  morsel, 
which  is  about  to  pass,  and  to  lay  the  curtain  back  at  the  same 
time,  so  as  to  be  a valve  for  the  nostrils,  and  for  the  mouth  of 
the  Eustachian  tube,  hindering  the  food  or  drink  from  entering 
into  these  passages. 

L.  The  ciRcuMFLEXus  PALATi,f  and  the  constrictor  isthmi 
faucium,  have  a very  different  use.  The  circumflexus  palati 
is  named  from  its  fibres  passing  over,  or  rather  under  the  hook 
of  the  internal  pterygoio,  process;  the  muscle  arises  along  with 
the  levator  palati,  (/.  e.)  from  the  sphenoid  bone  at  its  spi- 
nous process ; and  from  the  beginning  of  the  Eustachian  tube, 

the  thyroid  cartilage  to  the  epiglottis.  Along  with  this  muscle  may  he  claspd  the  set  of  fibres 
which  are  seen  sometimes  running  from  the  arytenoid  cartilage  to  the  epiglottis,  and  called 
aryteno  epigloLtideus. 

* From  the  Eustachian  tube,  it  was  named  salpingo  staphilinus  ; from  the  sphenoid 
bone,  spheno  staphilinus  ; from  the  pterygoid  process,  pterygo  staphilinus  ; from  the 
petrous  process  it  was  named  petro  salpingo  staphilinus  ; as  if  there  were_  no  science  but 
where  tliere  were  hard  names,  and  as  if  the  chief  mark  of  genius  were  enriching  the  hardest 
names  with  all  possible  combinations  and  contortions  of  them. 

t This  also,  has  got  a tolerable  assortment  of  hard  names,  as  circumelexus  palati, 
TENSOR  palati,  palato  salpi.ngeus,  staphelinus,  externus,  spheno-salp^go-staphy- 
IlNUS,  MUSCULUS  TUB.E,  viz.  EUSTACHIANA3  NONUS.  PtERYGO-STAPHILINUS  of  CowpeP,  &C. 


LOWER  JAW,  THROAT,  AND  TONGUE.  167 

it  runs  down  along  the  tube,  in  the  hollow  betwixt  the  ptery- 
goid processes ; it  then  becomes  tendinous,  turns  under  the 
book  of  the  internal  pterygoid  process,  and  mounts  again  to 
the  side  of  the  v»lum.  Now  the  levator  and  circumflexus  arise 
from  the  same  points  ; but  the  levator  goes  directly  downwards 
into  the  velum  and  so  is  useful  in  lifting  it  up.  The  circumflexus 
goes  round  the  hook,  runs  on  it  as  on  a pulley,  turns  upwards 
again,  and  so  it  pulls  down  the  palate,  and  stretches  it,  and 
thence  is  very  commonly  named  the  tEi'isor  palati  mollis, 
or  stretcher  of  the  palate.* 

LI.  The  constrictor  isthmi  faucitjm  arises  from  the 
very  root  of  the  tongue  on  each  side,  goes  round  to  the  mid- 
dle of  the  velum,  and  ends  near  the  uvula.f  This  semi-circle 
forms  that  first  arch  which  presents  itself,  upon  looking  into  the 
mouth.  , 

LII.  The  PALATO-PHARYNGEUsf  again  forms  a second  arch 
behind  the  first ; for  it  begins  in  the  middle  of  the  soft  palate, 
goes  round  the  entry  of  the  fauces,  ends  in  the  wing  or  edge 
of  the  thyroid  cartilage  ; and  as  the  first  arched  line  (that  form- 
ed by  the  constrictor,)  belonged  to  the  root  of  the  tongue, 
the  second  arched  line  belongs  to  the  pharynx  or  gullet.^ 
The  circumflexus  palati  makes  the  curtain  of  the  palate  tense, 
and  pulls  it  downwards : the  constrictor  faucium  helps  to  pull 
down  the  curtain,  and  raises  the  root  of  the  tongue  to  meet  it; 
the  palato-pharyngeus  farther  contracts  the  arch  of  the  fauces, 
which  is  almost  shut  upon  the  morsel  now  ready  to  be  forced 
down  into  the  stomach,  by  those  muscles  which  compress  the 
pharynx  itself. 

The  PHART.Nx,  which  is  the  opening  of  the  gullet,  that  it 
may  receive  freely  the  morsel  of  food,  is  expanded  into  a large 
and  capacious  bag,  which  hangs  from  the  basis  of  the  skull,  is 
chiefly  attached  to  the  occipital  bone,  the  pterygoid  processes, 
and  the  back  parts  of  either  jaw-bone.  The  (esophagus  again 
is  the  tube  which  conveys  the  food  down  into  the  stomach, 
and  this  bag  of  the  pharynx  is  the  expanded  or  trurapet-like 
end  of  it ; or  it  may  be  compared  with  the  mouth  of  a funnel. 
Towards  the  mouth,  the  pharynx  is  bounded  by  the  root  of  the 
tongue,  and  by  the  arches  of  the  throat ; behind,  it  lies  flat  and 

* Some  of  its  posterior  fibres  mix  with  the  constrictor  pharyngis  superior  and  palate 
pharyngeus. 

f Named  glosso  staphiliots,  from  its  ori^n  in  the  tongue,  and  insertion  into  the 

UVULA. 

X The  SALPiNGO-PHARVNGEcs  of  Alhious,  Is  no  more  tlian  that  part  of  the  palato-pha- 
ryngeus which  arises  from  the  moutli  of  the  Eustachian  tube. 

) In  its  passage  down,  its  fibres  are  mixed  with  the  stylo-pharyngeus,  and  in  its  insertion, 
fhey  are  mingled  with  the  inferior  constrictors. 


168 


MUSCLES  OF  THE 


smooth  along  the  bodies  of  the  vertebrse;  before,  it  is  protect- 
ed, and  in  some  degree  surrounded  by  the  great  cartilages  of 
the  larynx  ; the  horns  of  the  os  byoides  embrace  its  sides,  and 
it  is  covered  with  flat  muscular  fibres,  which,* arising  from  the 
os  byoides  and  cartilages  of  the  throat,  go  round  the  pharynx 
in  fair  and  regular  orders,  and  are  named  its  constrictors,  because 
they  embrace  it  closely,  and  their  contractions  force  down  the 
food. 

LIII.  The  STYLO-PHARYNGEus  arises  from  the  root  of  the 
styloid  process.  It  is  a long  slender  and  beautiful  muscle  ; ir 
expands  fleshy  upon  the  side  of  the  pharynx ; extends  so  far 
as  to  take  a hold  upon  the  edge  of  the  thyroih'  cartilage  ; it 
lifts  the  pharynx  up  to  receive  the  morsel,  and  then  straightens 
and  compresses  the  bag,  to  push  the  morsel  down,  and  by  its 
hold  upon  the  thyroid  cartilage  it  commands  the  larynx  also, 
and  the  whole  throat. 

The  pharynx  being  surrounded  by  many  irregular  points  of 
bone,  its  circular  fibres  or  constrictors  have  many  irregular 
origins.  The  constrictor  might  fairly  enough  be  explained  as 
one  muscle,  but  the  irregular  origins  split  the  fibres  of  the  mus- 
cle, and  give  occasion  of  dividing  the  constrictor  into  distinct 
parts;  for  one  bundle  arising  from  the  occipital  bone  and  os 
petrosum,  from  the  tongue,  the  pterygoid  process,  and  the  two 
jaw-bones,  is  distinguished  as  one  muscle,  the  constrictor- 
superior.*  Another  bundle  arising  from  the  os  hyoides  is 

named  the  constrictor  medius.f  A third  bundle,  the  lowest 
of  the  three,  arising  from  the  thyroid  and  cricoid  cartilages,  is 
named  the  constrictor  inferior. J 

LIV.  The  CONSTRICTOR  SUPERIOR  arising  from  the  basis  of 
the  skull,  from  the  jaws,  from  the  palate,  and  from  the  root  of 
the  tongue,  surrounds  the  upper  part  of  the  pharynx ; and  it 
is  not  one  circular  muscle,  but  two  muscles  divided  in  the  mid- 
dle line  behind,  by  a distinct  rapha,  or  meeting  of  the  opposite 
fibres.l^ 

LV.  The  CONSTRICTOR  MEDius  rises  chiefly  from  the 
round  point  in  which  the  os  hyoides  terminates ; it  also  arises 
from  the  cartilage  of  the  os  hyoides  (f.  e.)  where  the  horns 
are  joined  to  the  body.  The  tip  of  the  horn  being  the  most 
prominent  point,  and  the  centre  of  this  muscle,  it  goes  upwards 

* These  good  opportunities  of  names  have  not  been  disregarded ; this  muscle  has  been 

named  CEPHALO-rllARYNGEUS,  PTEHYG0-PI!AEYNQEU8,  MtlO  PIIARYNGEUS,  GLOSSO-PHARYN- 
GEUS. 

f This  one  is  named  hyopharyngeus,  or  syndesmo  pharyncegs,  from  its  origin  in  the. 
cartilage  also  of  the  os  hyoides. 

t This,  of  course,  is  named  thyero-phabyngeus,  and  crico-pharysgeus. 

’ It  is  connected  with  the  buccinator,  the  root  of  the  tongue,  and  palate. 


LOWER  JAW,  THROAT,  AND  TONGUE. 


169 


and  downwards,  so  as  to  have  something  of  a lozenge-like 
shape ; it  lies  over  the  upper  constrictor  like  a second  layer, 
its  uppermost  peak,  or  pointed  part,  touches  the  occipital  bone, 
and  its  lower  point  is  hidden  by  the  next  muscle. 

LVI.  The  CONSTRICTOR  INFERIOR  arises  partly  from  the 
thyroid  and  partly  from  the  cricoid  cartilage ; and  it  again  goes 
also  obliquely,  so  as  to  overlap  or  cover  the  lower  part  of  the 
constrictor  raedius.  This,  like  the  other  two  constrictors, 
meets  its  fellow  in  a tendinous  middle  line ; and  so  the  morsel 
admitted  into  the  pharnyx  by  the  dilatation  of  its  arches,  is 
pushed  down  into  the  oesophagus  by  the  forces  of  these  con- 
strictores  pharyngis,  assisted  by  its  styloid  muscles.’ 

LVII.  The  (ESOPHAGUS  is  merely  the  continuation  of  the 
same  tube.  It  lies  flat  upon  the  back-bone,  and  it  is  covered 
in  its  whole  length  by  a muscular  coat,  which  is  formed,  not 
like  this  of  the  pharynx,  of  circular  fibres,  but  of  fibres  running 
according  to  its  length  chiefly.  And  this  muscle,  surrounding 
the  membraneous  tube  of  the  oesophagus  like  a sheath,  is 
named  (LVIII.)  vaginalis  gulje. 

MUSCLES  OF  THE  TONGUE. 

The  muscles  of  the  tongue  are  large  bundles  of  fle^  which 
come  from  the  os  hyoides,  the  chin,  and  the  styloid  process. 
Their  thickness  constitutes  the  chief  bulk  of  the  tongue.  Their 
actions  perform  all  its  motions. 

LIX.  The  HYOGLossus  is  a comprehensive  name  for  all 
those  which  arise  from  the  os  hyoides.  The  muscles  from  the 
os  hyoides  go  oflT  in  three  fasciculi,  and  were  once  reckoned 
as  distinct  muscles.  That  portion  which  arises  from  the  basis 
of  the  os  hyoides  was  called  basioglossus  ; that  which  arises 
from  the  cartilaginous  joining  of  the  body  and  horn  was  called 
CHONDROGLOSsus;  and  that  which  arises  from  the  horn  itself 
was  named  ceratoglossus  ; or  the  terms  were  all  bundled  to- 
gether in  the  perplexed  names  of  basio-chondro-cerato-glos- 
sus. 

The  hyoglossus,  then,  is  all  that  muscular  flesh  which  arises 
from  the  whole  length  of  the  os  hyoides,  and  which,  by  the 
changing  form  of  the  bone  in  its  basis,  cartilage,  and  horn,  has 
a slight  mark  of  division,  but  which  lie  all  in  one  plain,  and 
need  not  have  distinct  names. 

T.X.  The  GENio  HYOGLOSSUS  arises  from  the  rough  tubercle 
behind  the  symphisis  of  the  chin.  It  has  a very  narrow  or 
pointed  origin  ; it  spreads  out  fan-like,  as  it  goes  towards  the 

VOL.  I.  Y 


170  MUSCLES  OE  THE  LOWER  JAW,  &C. 

tongue  and  base  of  the  os  hyoides ; and  it  spreads  with  radii., 
upwards  and  backwards,  making  the  chief  part  of  the  substance 
of  the  tongue. 

LXI.  The  LiNGUALis  is  an  irregular  bundle  of  fibres,  which 
runs  according  to  the  length  of  the  tongue  ; it  lies  betwixt  the 
genio  hyoglossus  and  the  byoglossus,  and  as  it  is  in  the  centre, 
and  unconnected  with  any  bone,  it  is  named  lingualis,  as  aris- 
ing in  the  tongue  itself. 

The  genio  hyoglossi  muscles  from  by  far  the  larger  part  of 
the  tongue,  and  lie  in  the  very  centre.  They  go'through  the 
whole  length,  (i.  e.)  from  the  root  to  the  tip  of  the  tongue,  and 
from  the  radiated  form  of  their  fibres  they  perform  every 
possible  motion ; whence  this  was  named  by  Winslow,  mus- 
culus  POLYCHRESTUS,  fop  its  rays  proceed  from  one  point  or 
centre,  and  those  which  go  to  the  point  of  the  tongue  pull  the 
tongue  backwards  into  the  mouth.  Those  which  go  backwards 
thrust  the  tongue  out  of  the  mouth.  The  middle  fibres  acting, 
make  the  back  of  the  tongue  hollow,  while  the  tip  and  the  root 
of  the  tongue  both  rise. 

The  hyoglossi  muscles  lie  on  either  side  of  the  genio- 
hyoidasi,  and  make  up  the  sides  of  the  tongue,  and  their  chief 
action  would  seem  to  be  this,  that  the  hyoglossus  muscle  of 
either  side  acting,  the  edges  of  the  tongue  would  be  pulled 
downwards,  and  the  back  rounded,  the  opposite  of  which 
motion  is  the  genio-byoidaei  acting,  by  which  the  middle  of 
the  tongue  is  made  into  a groove,  the  edges  rising,  and  the 
centre  being  depressed.  Lastly,  The  styloglossus  is  plainly 
intended  for  drawing  the  tongue  deep  into  the  mouth,  parti- 
cularly affecting  the  point  of  the  tongue. 


( ni  ) 


CHAP.  III. 

OF  THE  MUSCLES  OF  THE  ARM, 

INCLUDING  THE  MUSCLES  OF  THE  SCAPULA,  ARM,  FORE-ABM, 
AND  HAND. 

MUSCLES  OF  THE  SCAPULA. 

The  great  peculiarity  of  the  arm  is,  the  manner  of  its  con- 
nection with  the  breast,  to  which  it  is  fixed  by  the  slight  liga- 
ments of  the  clavicle  only : but  its  union  to  the  body  is  secured 
by  its  strong  and  numerous  muscles,  by  which  indeed  it  may 
be  said  both  to  be  fixed  and  moved.  Though  it  were  perhaps 
more  regular  to  describe  first  the  muscles  of  the  trunk,  it  will 
be  more  easy  and  natural  to  describe  first  the  broad  muscles, 
belonging  to  the  scapula,  which  cover  almost  the  whole  trunk, 
and  hide  its  proper  muscles,  viz.  those  which  move  the  ribs 
and  spine.  For  the  muscles  which  move  the  scapula  lie  upon 
the  trunk ; those  which  move  the  arm  lie  upon  the  scapula ; 
those  which  move  the  fore-arm  lie  upon  the  arm ; and  those 
for  moving  the  hand  and  fingers  lie  upon  the  fore-arm.  The 
leg  requires  but  one  chief  motion,  viz.  backwards  and  forwards, 
flexion  and  extension.  It  has  no  other  motions  than  those  of  the 
thigh  and  of  the  knee  ; but  the  arm  requires  an  easy  and  cir- 
cular motion,  and  its  joints  are  multiplied : for  it  has  the  wrist 
turning  round  ; it  has  the  elbow  for  hinge-like  motions  ; it  has 
the  shoulder-joint  upon  which  the  arm  rolls ; and  to  assist  all 
these,  the  scapula,  which  is  the  centre  of  all  these  motions,  is 
itself  moveable  ; after  a certain  point  of  elevation,  all  the  mo- 
tion in  raising  the  arm  is  performed,  not  by  the  motions  of  the 
shoulder-bone  upon  the  scapula,  but  by  the  scapula  upon  the 
trunk.  For  whenever  the  shoulder-bone  rises  to  the  horizon- 
tal direction,  it  is  checked  by  the  acromion,  which  hangs  over 
it;  and  if  the  arm  is  to  be  raised  higher  still,  the  scapula  must 
roll ; it  turns  upon  the  point  of  the  clavicle,  and  in  turning,  it 
glides  upon  those  muscles,  which  are  like  a cushion  betwixt  it 
and  the  trunk. 

The  muscles  which  move  the  scapula,  come  from  the  breast 
to  move  it  forwards ; from  the  neck,  to  move  it  upwards ; from 
the  spines  of  the  vertebrae,  to  move  it  backwards ; and  from 
the  side,  that  is,  from  the  ribs,  to  move  it  downwards. 

LXII.  The  TRAPEZIUS  is  named  from  its  lozenge  form  ; or 
is  often  named  cucularis,  from  its  resembling  the  monk’s 
cowl,  hanging  back  upon  the  neck,  It  is  one  of  the  most 


17!i  MUSCLES  OF  THE  ARM,  &C. 

beautiful  muscles  in  the  body ; and  the  two  muscles  together 
cover  all  the  shoulders  and  neck,  with  a lozenge-like  form, 
with  neat  and  sharp  points,  extending  from  the  lip  of  one 
shoulder  to  the  tip  of  the  other,  and  from  the  nape  of  the 
neck  quite  down  to  the  loins.  It  arises  from  the  most  pointed 
part  of  the  occipital  bone,  and  along  the  transverse  spine  quite 
to  the  mastoid  process,  by  a thin  membranous  tendon ; from 
this  point  all  down  the  neck,  it  has  no  hold  of  the  vertebrae, 
but  arises  from  its  fellow  in  a strong  tendon,  which,  extending 
like  a bow-string  down  the  neck,  over  the  arch  of  the  neck, 
and  not  touching  the  vertebrae,  till  it  comes  down  to  the  top 
of  the  back,  is  named  ligamentum  noch.®.  The  tendon  be- 
gins again  to  take  hold  of  the  spines  of  the  two  last  vertebrae  of 
the  neck,  and  arises  from  all  the  spinous  processes  of  the  back, 
dovftnwards;  from  this  long  origin  its  fibres  converge  towards 
the  tip  of  the  shoulder  : it  also  comes  a little  forward  over  the 
side  of  the  neck. 

It  is  implanted  into  more  than  one-third  of  the  clavicle  near- 
est the  shoulder;  into  the  tip  of  the  acromion  ; into  tlie  whole 
length  of  the  spine,  from  which  the  acromion  rises  ; and  its 
fibres  arising  from  along  the  neck  and  back,  and  converging 
almost  into  a point,  must  have  various  elfects,  according  to  the 
different  fibres  which  act : for  those  which  come  downwards 
must  raise  the  scapula;  those  which  come  from  the  middle  of 
the  back  must  carry  it  directly  backwards ; those  which  come 
from  the  lower  part  of  the  back  must  depress  it ; and  those 
different  fibres  acting  in  succession,  must  make  the  scapula 
roll.  The  trapezius  is  chiefly  a muscle  of  the  scapula,  but  it 
must  be  also  occasiDnally  a muscle  of  the  bead,  pulling  the 
head  backwards,  and  bending  the  neck. 

Three  other  muscles  which  raise  the  scapula,  or  carry  it 
backwards,  lie  so  much  in  the  same  plane,  and  are  so  little 
divided  from  each  other,  that  they  might  almost  be  reckoned 
different  portions  of  the  same. 

LXIil.  Levatok  scapul®,  named  also  levator  propjuus 
ANGULAKis,  is  a Small  thin  slip  of  flesh,  which  arises  from  the 
four  or  five  uppermost  vertebrae  of  the  neck,  at  their  transverse 
processes,  by  three  or  four  and  sometimes  five  distinct  heads. 
The  heads  join  to  form  a thin  and  flat  stripe  of  muscle,  about 
three  inches  in  breadth,  which  is  fixed  by  a flat  thin  tendon  to 
the  upper  corner  of  the  scapula,  to  pull  it  upwards,  as  in  shrug- 
ging the  shoulders ; whence  itis  named  musuulus  patientije. 

LXIV.  and  LXV.  The  rhomboid  muscle  stretches  flat, 
neat,  and  of  a square  form,  betwixt  the  spine  and  the  Avhole 
line  of  the  base  of  the  scapula.  One  part  arises  from  the  three 
lower  spinous  processes  of  the  neck,  and  is  implanted  into  the 


MUSCLES  OP  THE  ARM,  &C.  17^ 

base  of  the  scapula  higher  than  the  rising  of  the  spine  of  the 
scapula  j another  portion  arises  from  the  spinous  processes  of 
the  first  four  vertebrae  of  the  back,  runs  exactly  in  the  same 
plane  with  the  other  into  the  base  of  the  scapula  below  the 
spine.*  The  part  arising  from  the  three  vertebras  of  the  neck 
is  slightly  divided  from  that  which  arises  from  the  four  verte- 
brae of  the  back,  though  not  distinctly,  and  often  not  at  all.  I 
would  reckon  this  but  one  muscle,  but  it  has  been  commonly 
distinguished  into  (LXIV.)  the  rhomboideus  minor,  the  up- 
permost portion,  and  (LXV.)  the  rhomboideus  major,  the 
lower  portion.  These  are  seen  after  raising  the  trapezius ; 
and  the  uses  of  the  trapezius,  levator  scapulae,  and  rhomboi- 
deus, are  to  raise  the  scapula  or  to  carry  it  backwards.  The 
muscles  which  move  the  scapula  downwards  and  forwards,  viz. 
the  pectoralis  minor  and  the  serratus  major  anticus,  lie  upon 
the  forepart  of  the  breast. 

LXVI.  The  SERRATUS  major  anticus  lies  upon  the  side: 
of  the  chest  arising  from  the  ribs ; and  as  the  ribs  have  in- 
terstices betwixt  them,  every  muscle  arising  from  the  ribs  arises 
by  distinct  portions  from  each  rib  : all  such  distinct  and  point- 
ed slips  are  named  digitations,  tongues,  or  serrae,  from  their 
resembling  the  teeth  of  a saw;  and  every  muscle  arising  from 
the  ribs  must  be  a serrated  muscle.  Tbe  serratus  major  anticus 
is  that  great  and  broad  muscle,  the  chief  part  of  which  lies  un- 
der the  scapula  ; and  nothing  of  which  is  seen  but  the  fleshy 
tongues,  by  which  it  arises  from  the  sides  of  the  ribs.  It  is  all 
fleshy,  and  is  of  a considerable  breadth  and  strength  : it  arises 
from  all  the  true  ribs  : it  sometimes  misses  the  first  rib;  and 
from  three  of  the  false  ribs  : its  indigitations,  of  course,  spread 
all  over  the  side  of  the  thorax  like  a fan  : its  upper  indigitations 
lie  under  the  pectoralis  major,  and  its  lower  indigitations  are 
mixed  with  the  beginning  of  the  external  oblique  muscle  of  the 
abdomen.  Its  middle  indigitations  are  seen  spreading  upon 
the  sides  of  the  thorax : it  lies  thick  and  fleshy  under  the 
scapula,  and  is  a part  of  that  cushion  on  which  the  scapula 
glides : its  fibres  converge  towards  a narrower  insertion ; and 
the  muscle  ends  thick  and  fleshy  in  the  whole  length  of  that 
line  which  we  call  the  basis  of  the  scapula,  and  is  as  it  were 
folded  round  it ; so  that  this  muscle,  which  comes  from  before, 
is  implanted  along  with  the  rhomboideus,  which  comes  from 
behind. 

Perhaps,  in  difficult  breathing,  the  shoulder-blade  being- 
raised  and  fixed  by  its  own  muscles,  the  serratus  major  may 

^ We  frequently  indeed  almost  find  that  the  rhomboideus  major  tates  al-Jo  an  origin  from 
'.he  7th  cendcal  vertebra ; it  i?  so  expressed  in  Albinus. 


174  MUSCLES  OP  THE  ARM,  &C. 

assist  in  heaving  up  the  ribs ; but  its  chief  operation  is  upon 
the  scapula ; for  when  the  whole  acts,  it  pulls  the  scapula 
downwards  and  forwards.  When  only  the  lower  portions  act, 
it  pulls  the  lower  angle  of  the  scapula  forwards,  by  which  the 
scapula  rolls,  and  the  tip  of  the  shoulder  is  raised  ; when  the  ] 
upper  part  acts  in  conjunction  with  the  little  pectoral  muscle,  j 
the  tip  of  the  shoulder  is  fixed  and  pulled  downwards  towards  I 

the  chest,  and  the  lower  corner  of  the  scapula  rolls  back-  I 

wards.  j 

LXVII.  The  PECTORALis  MINOR  lies  under  the  pectoralis 
ina,jor,  close  upon  the  ribs ; and  as  it  arises  from  the  third, 
fourth,  and  fifth  ribs,  it  sometimes  takes  its  origin  from  the 
second,  third,  and  fourth  ribs,  and  sometimes  only  from  the 
third  and  fourth  ; it  also  is  a serrated  muscle,  and  was  named 
serratus  minor  anticus  : its  three  digitations  are  very  thick  and 
fleshy ; they  soon  converge  so  as  to  form  a small,  but  thick  and 
fleshy  muscle,  which,  terminating  in  a point,  is  inserted  into  • 
the  very  apex  of  the  coracoid  process  : by  pulling  the  coracoid 
process  forwards  and  downwards,  it  will  roll  the  shoulder. 

LXVIII.  The  SUBCLAVIAN  muscle  is  another  concealed 
muscle  of  the  scapula  ; for  the  clavicle  is  just  the  hinge  upon 
which  the  scapula  moves,  and  the  subclavian  muscle  arises  by 
a flat  tendon  from  the  cartilage  of  the  first  rib  ; it  becomes  flat 
and  fleshy,  and  lies  along  betwixt  the  clavicle  and  the  first  rib ; | 

it  arises  at  a single  point  of  the  rib,  flat  and  tendinous ; but  it  | 

is  inserted  into  a great  length  of  the  clavicle,  beginning  about 
two  inches  from  the  sternum,  and  being  inserted  all  along  the  j 
clavicle,  quite  out  to  where  it  is  joined  to  the  acromion  pro-  i 
cess  : its  chief  use  (since  the  rib  is  immoveable)  must  surely  : 
be  to  pull  the  clavicle,  and  consequently  the  shoulder  down- Ml 
wards,  and  so  to  fix  them.  > 

Many  have  affected  to  find  other  muscles  of  respiration  than  ™' 
those  which  directly  belong  to  the  ribs.  Among  these  are 
reckoned  the  serratus  major,  the  pectoralis  minor,  &ic.  ; but 
there  is  much  reason  to  doubt  whether  any  muscles  can  have 
much  effect  which  do  not  belong  properly  to  the  ribs : and  it 
is  manifest,  that  the  subclavian  can  have  none,  since  the  first 
I’ib  is  quite  rigid,  has  so  little  length  of  cartilage,  that  it  cannot 
bend  nor  move. 

The  scapula  is  thus  moved  in  every  possible  direction  up- 
wards, by  the  levator  and  the  trapezius ; backwards  by  the 
rhomboideus,  assisted  by  the  middle  portions  of  the  trapezius  ; 
downwards  and  backwards  by  the  lowest  order  of  fibres  in  the 
trapezius;  downwards  and  forwards  by  the  serratus  major  anti- 
cus ; directly  downwards  by  the  serratus,  balanced  by  the 


175 


MUSCLES  OF  THE  ARM,  &C. 

trapezius,  and  assisted  by  the  subclavius ; and  directly  forwards 
by  the  pectoralis  minor. 

MUSCLES  OF  THE  AHM; 

VIZ.  THOSE  MOVING  THE  OS  HUMERI,  OR  ARM-BONE. 

LXIX.  The  PECTORALEs  MAJOR  is  a large,  thick,  and  fleshy 
muscle  which  covers  all  the  breast.  It  arises  from  the  half  of 
the  clavicle  next  the  sternum  ; from  all  the  edge  of  the  sternum, 
the  cartilaginous  endings  of  the  three  lower  true  ribs.*— 
Where  it  arises  from  the  sternum,  it  is  tendinous,  and  the  fibres 
from  the  opposite  muscles  cross  and  mix,  so  as  to  make  a sort 
of  fascia  covering  the  bone.  It  is  fleshy  where  it  arises  from 
the  ribs,  and  there  it  mixes  with  the  external  abdominal  mus- 
cle. The  fibres  approach  each  other  till  they  form  a flat  ten- 
don about  an  inch  in  breadth  ; and  as  the  fibres  approach  each 
other,  they  cross  in  such  a way,  that  the  lower  edge  of  the 
muscle  forms  the  upper  edge  of  the  tendon,  which  is  still  flat, 
but  twisted  ; its  implantation  is  into  the  edge,  if  I may  call  it 
so,  of  the  groove  or  rut  of  the  biceps  tendon.  That  part 
which  arises  from  the  clavicle  is  a little  separated  from  that 
which  arises  from  the  sternum  ; a fatty  line  makes  the  distinc- 
tion ; and  they  are  sometimes  described  as  two  parts  : it  is 
those  two  bundles  chiefly  which  cross  ^ach  other  to  make  the 
plaited  appearance.  The  pectoralis,  among  others,  has  been 
made  a muscle  of  respiration.f 

LXX.  The  LATissiMus  dorsi  is  the  broadest,  not  only  of 
the  back,  but  perhaps  of  the  whole  body.  It  is  a beautiful 
muscle,  covering  all  the  lower  part  of  the  back  and  loins,  and 
reaching  to  the  arm,  to  be  the  antagonist  to  the  pectoral  mus- 
cle. It  arises  by  a broad,  flat,  and  glistening  tendon,  which  co- 
vers all  the  loins,  and  which  is  in  some  degree  the  root  of  other 
muscles,  especially  of  the  longissimus  dorsi.  This  broad  sil- 
very tendon  begins  exactly  in  the  middle  of  the  back  ; it  arises 
from  the  lower  vertebrae  of  the  loins,  from  the  spines  and  knobs 

* We  frequently  find  slips  running  as  distinct  muscles  from  the  7th  and  8th  rib  to  the  hu- 
merus ; they  have  been  remarked,  in  the  Windmill-street  dissecting-room,  more  'frequently 
in  Lascars  and  Negroes  tlian  in  Europeans.  In  December  1814,  a body  was  dissected,  in 
wliich  there  was  found  on  both  sides  a slip  of  fibres  1 8 indies  long,  extending  from  the  4th 
and  5th  rib  to  the  fascia,  between  the  triceps  and  brachialis  interims,  and  a distinct  slip 
tendon  might  be  traced  even  to  the  inner  condyle. 

t Haller  tells  us,  that  when,  at  any  time,  he  had  rheumatism  in  this  muscle,  his  breath- 
ing was  checked  ; and  when  he  had  dilficult  breathing,  he  found  great  relief  by  fixing  the 
hands,  raising  the  shoulders,  and  acting  with  the  pectoral  muscles.  It  seems  confirmed  by 
these  facts,  tliat  asthmatics  take  this  posture ; women  in  labour  fix  their  arms,  by  resting 
upon  the  arms  of  tlieir  chair ; those  who  play  on  wind  rastjraments  raise  the  shoulders  in 
strammg. 


176  MUSCLES  OP  THE  ARM,  &C. 

of  the  back  of  the  sacrum,  and  from  the  back  part  of  the  cir- 
cle of  the  os  ilium  ; this  last  is  the  only  part  that  is  fleshy. 
The  flat  tendon  gradually  passes  into  a flat  and  regular  muscle, 
which  wraps  round  the  side  of  the  body,  and  as  it  lies  over  the 
corner  of  the  scapula,  it  sometimes  receives  a small  fleshy 
bundle  from  it ; and  as  it  passes  over  the  four  lower  ribs,  it 
has  some  tendinous  slips  sent  into  it,  by  which  it  is  attached  to 
the  ribs.  Its  fibres  converge  : for  the  lower  ones  ascend ; the 
upper  ones  go  directly  across.  And  these  different  orders  not 
only  meet  to  form  its  flat  tendon,  but  they  cross  each  other, 
like  those  of  the  pectoral  muscle  : here  also  the  tendon  is 
twisted,  and  the  upper  edge  of  the  muscle  forms  the  lower 
edge  of  the  flat  tendon  ; which,  passing  into  the  axilla,  turns 
under  the  arm-bone,  and  is  implanted  into  it,  on  the  inner  edge 
of  the  bicipital  groove ; so  the  tendons  of  the  pectoralis  and 
latissimus  meet  each  other;  they,  in  fact,  join  face  to  face,  as 
if  the  one  tendon  ended  directly  in  the  other ; and  both  uni- 
ted, make  a sort  of  lining  for  the  groove,  or  a tendinous  sheath, 
for  the  long  tendon  of  the  biceps  to  run  on. 

These  two  muscles  form  the  axilla  or  arm-pit ; and  although 
each  has  its  peculiar  offices,  their  chief  operation  is  when  they 
coincide  in  one  action ; and  that  action  is  exceedingly  power- 
ful, both  by  the  great  strength  of  either  muscle,  and  by  their 
being  implanted  into  the  arm-bone,  four  inches  below  its  head. 
The  pectoralis  major  is  for  pulling  the  arm  forwards,  as  in  lay- 
ing the  arms  across  the  breast,  or  in  carrying  loads  in  the  arms  ; 
and  it  forms  the  border  of  the  axilla  before.  The  latissimus 
dorsi  has  a wider  range ; when  the  arm  is  raised,  it  brings  it 
downwards  as  in  striking  with  a hammer,  or  downwards  and 
backwards,  as  in  striking  with  the  elbow,  or  in  rolling  the  arm 
inwards  and  backwards,  as  in  turning  the  palm  of  the  hand  be- 
hind the  back,  whence  it  has  the  obscene  name  of  musctjlus 
scALPTOR  ANi,  OP  TERSOR  ANi ; and  it  forms  the  back  edge  of 
the  axilla.  The  edges  of  these  two  muscles  receive  the  pres- 
sure of  crutches,  and  defend  the  vessels  and  nerves  ; when  both 
muscles  act,  the  arm  ispressed  directly  downwards,  as  in  rising 
from  our  seat,  or  in  holding  a bundle  under  the  arm  ; or  when 
the  arm  is  fixed,  these  muscles  raise  the  body  as  in  the  exam- 
ple just  mentioned,  of  rising  from  our  seat,  or  in  walking  with 
a short  stick,  or  in  raising  ourselves  by  our  hands  over  a high 
beam. 

LXXI,  The  DELTOiDES  is  the  first  of  those  muscles  which 
arise  from  the  scapula,  to  be  inserted  into  the  shoulder-bone. 
It  is  named  deltoid  muscle,  from  its  resembling  the  letter  A of 
the  Greeks ; it  is  thick  and  fleshy,  and  covers  the  top  of  the 
shoulder,  filling  up  the  space  betwixt  the' acromion  process  and 


17? 


MUSCLES  OF  THE  ARM,  &C. 

the  shoulder-bone  ; it  arises  from  all  that  part  of  the  clavicle, 
which  is  not  occupied  by  the  pectoralis  muscle,  and  is  separated 
from  it  only  by  a fatty  line  ; it  arises  again  in  another  bundle, 
from  the  point  of  the  acromion  process,  and  this  middle  bun- 
dle is  also  insulated  by  a fatty  line  on  either  side  of  it.  The 
third  bundle  arises  from  the  spine  of  the  scapula,  behind  the 
acromion  process,  and  which  is  also  attached  to  the  base  by  a 
strong  ligamentous  fascia,  which  covers  the  infra  spinatus  mus- 
cle. And  thus  the  muscle  has  three  converging  heads,  viz.  a 
head  from  the  outer  end  of  the  clavicle,  a head  from  the  acro- 
mion, or  tip  of  the  shoulder,  a head  from  the  ridge  of  the  spine, 
each  divided  from  the  other  by  a fatty  line.*  These  heads  or 
bundles  of  fibres,  meeting  about  one-third  down  the  humerus, 
form  a short,  flat,  and  strong  tendon,  which  grasps  or  almost 
surrounds  the  shoulder-bone. 

These  three  distinct  heads  must  be  observed  in  speaking  of 
the  use  of  the  muscle  ; for  though  the  chief  use  of  the  muscle 
be  to  raise  the  arm,  this  is  not  the  use  of  it  in  all  circumstan- 
ces ; for  the  outer  and  inner  heads,  lying  by  the  side  of  the 
shoulder-bone,  and  below  the  joint,  do,  when  the  arm  is  lying 
flat  by  the  side,  assist  the  pectoral,  and  latissimus  dorsi  muscles 
in  drawing  it  close  to  the  side.  But  when  the  middle  bundle 
raises  the  arm,  in  proportion  as  the  middle  bundle  raises  the 
arm,  it  loses  of  its  power ; and  in  proportion  as  it  loses  of  its 
power,  the  side  portions,  having  come  into  a new  direction,  be- 
gin to  help  : nay,  when  the  arm  is  raised  to  a certain  point, 
more  power  still  is  required,  and  the  clavicular  part  of  the  pec- 
toral muscle  also  comes  to  assist.  It  is  in  this  succession,  that 
the  several  bundles  of  fibres  act ; for  if  they  began  all  at  once 
to  act,  the  arm  should  rather  be  bound  down  by  the  lateral  por- 
tions, than  raised  by  the  middle  one. 

LXXII.  CoRAco  BRACHiALis. — The  coraco  brachialis,  so 
named  from  its  origin  and  insertion,  is  a long  and  rather  slender 
muscle. 

It  arises  from  the  coracoid  process  of  the  scapula,  along 
with  the  short  head  of  the  biceps  muscle,  and  it  is  closely  con- 
nected with  this  head,  almost  its  whole  length  : it  is  small  at  its 
beginning ; it  grows  gradually  thicker  as  it  decends ; it  is  all 
fleshy,  and  is  inserted  by  a very  short  tendon  into  the  os  hu- 
meri, nearly  about  its  middle,  betwixt  the  bracbialis  and  the 
third  head  of  the  triceps.  It  is  perforated  by  the  external  cu- 
taneous nerve.  This  was  observed  by  Casserius,  an  Italian 
anatomist ; and  the  muscle  is  often  named  musculus  perfo- 

RATUS  CASSERII. 


* Albinus  has  distinguished  it  into  seven  fasciculi  or  bundles;  a very  saperfliioa®  aecora'oy 

VOL.  I.  Z 


178 


MUSCLES  OF  THE  ARM,  &C. 

Its  action  is  very  simple,  to  raise  the  arm  obliquely  forwards 
and  upwards,  and  consequently  to  give  a degree  of  rotation. 
It  will  also  have  a chief  effect  in  pulling  the  arm  towards  the 
side  of  the  body. 

LXXIIL  The  supra  spinatus  is  so  named  from  its  oc- 
cupying the  hollow  of  the  scapula  above  the  spine. 

It  arises  from  the  back  of  the  scapula,  reaching  to  the  base, 
from  the  spine,  and  from  the  superior  edge  or  costa;  it  is  ex- 
ceedingly thick  and  fleshy,  filling  up  all  the  hollow  between 
the  spine  and  superior  costa ; and  it  is  firmly  enclosed  in  this 
triangular  hollow,  by  a strong  tendinous  expansion,  which 
passes  from  the  superior  edge  of  the  scapula,  to  the  ridge  of 
the  spine  ; it  is  consequently  a muscle  of  a triangular  figure, 
thick  and  strong ; it  passes  under  the  acromion,  and  degene- 
rates into  a tendon  there,  and  going  under  the  acromion,  as 
under  an  arch,  and  over  the  ball  of  the  humerus,  it  adheres  to 
the  capsule  of  the  shoulder-joint,  and  is  at  last  implanted  by  a 
broad  strong  tendon  into  the  upper  part  of  the  great  tuberosity 
on  the  head  of  the  bone. 

It  is  evidently  designed  for  raising  the  humerus  directly 
upwards,  and  by  its  attachment  to  the  capsule,  the  capsule  is 
drawn  up  when  the  arm  is  raised,  so  that  though  lax,  it  cannot 
be  caught  in  the  joint.  It  exactly  performs  the  same  motion 
with  the  middle  part  of  the  deltoiues,  lies  in  the  same  direc- 
tion with  it,  and  assists  it. 

LXXIV.  Infra  spinatus,  is  like  the  former  in  all  respects, 
of  the  same  use,  and  assisting  it. 

This  also  is  of  a triangular  shape,  and  is  fully  one  half  larger 
than  the  supra  spinatus ; and  the  supra  spinatus  arises  from  all 
the  triangular  cavity  above  the  spine  : this  arises  from  almost 
all  the  triangular  cavity  below  it. 

It  arises  fleshy  from  all  the  back  of  the  scapula  below  the 
Spine,  except  that  part  giving  origin  to  the  teres  major  and 
minor,  from  the  spine  itself,  and  from  all  the  base  of  the  sca- 
pula, below  the  beginning  of  the  spine,  and  also  from  the 
greater  part  of  the  lower  costa  of  the  scapula.  It  i« 
very  thick  and  strong,  almost  filling  up  the  triangular 
cavity,  and  it  is  closed  in  like  the  former,  by  a strong 
tendinous  expansion ; it  begins  to  grow  tendinous  about 
its  middle,  but  it  continues  also  fleshy  till  it  passes  over 
the  socket  of  the  shoulder-joint : it  also  is  connected  with  the 
capsular  ligament,  is  inseried  into  the  middle  of  the  same  tu- 
berosity with  the  former,  and  has  exactly  the  same  uses,  viz. 
preventing  the  capsule  from  being  caught  in  the  joint,  and 
raising  the  arm  upwards,  and  inclining  it  a little  outwards,  by  a 
slight  degree  of  rotation.  And  I do  believe,  that  one  great  use 


179 


MUSCLES  OF  THE  ARM,  &C. 

•f  these  two  muscles  is,  when  the  arm  is  much  extended  back- 
wards, to  prevent  the  head  of  the  humerus  from  starting  out  of 
its  superficial  socket. 

LXXV.  The  TCftKs  MINOR  is  a third  muscle  which  co-ope- 
rates with  these.  This  and  another  are  so  named  from  their 
appearance,  not  from  their  shape,  for  they  seem  round  when 
superficially  dissected,  because  then  their  edges  only  are  seen  : 
but  when  fully  dissected  from  the  other  muscles,  they  are  ra- 
ther flat.  The  teres  minor  is  a long,  small,  fleshy  muscle  ; it 
arises  from  the  angle,  and  all  the  lower  edge  of  the  scapula  : it 
is  like  the  infra  spinatus;  it  becomes  earl}  tendinous  ; but  the 
tendon  is  accompanied  with  fleshy  fibres  from  below ; its  flat 
tendon,  in  passing  over  the  joint,  is  attached  to  the  capsule, 
and  is  finally  inserted  into  the  great  tuberosity  of  the  shoulder- 
bone,  so  that  it  must  have  exactly  the  same  uses  as  the  two 
former  muscles.  It  is  separated  from  the  infra  spinatus  by 
that  tendinous  expansion  with  which  the  latter  is  covered  ; it 
looks  like  a part  of  the  same  muscle  in  its  origin,  where  it  lies 
upon  the  scapula ; but  is  very  distinct  in  its  tendon.  The  su- 
pra spinatus,  infra  spinatus,  and  teres  minor,  raise  the  arm. 

LXXVI.  The  TEKEs  MAJOR  is  in  shape  like  the  former,  lies 
lower  upon  the  edge  of  the  scapula  than  the  teres  minor,  and 
is  thicker  and  longer  than  it. 

It  arises  chiefly  from  the  angle  of  the  scapula ; partly  from 
the  lower  edge  of  the  scapula,  at  its  back  part ; it  is  connected 
with  the  TERES  minor,  and  infra  spinatus.  It  is  a large, 
thick,  and  flat  muscle,  and  forms  a flat  strong  tendon,  which 
passes  under  the  long  head  of  the  triceps;  it  passes  under  the 
os  humeri ; turns  round  it,  and  is  inserted  into  the  ridge,  on 
the  inner  side  of  the  groove,  and  gives  some  tendinous  fibres 
to  line  the  groove.  In  short,  it  accompanies  the  tendon  of  the 
latissimus  dorsi,  is  inserted  along  witjj  it,  and  may  be  consider- 
ed as  the  congenor  of  the  latissimus  dorsi ; and  the  two  ten- 
dons are  inclosed  in  one  common  capsule,  or  sheath  of  cellular 
substance. 

Its  use,  then,  is  evidently  to  draw  the  humerus  downwards 
and  backwards,  and  to  perform  the  same  rotation  of  the  arms, 
which  the  latissimus  dorsi  does. 

LXXVII.  The  subscapularis  lines  all  the  concavity  of 
the  scapula  like  a cushion.  It  is  like  the  surface  of  the  scapula 
on  which  it  lies,  of  a triangular  shape  ; and  from  the  conver- 
gence of  all  the  fibres  it  is  completely  l adiated  or  fan-like  ; it 
is  very  fleshy,  thick,  and  strong ; the  radii  are  each  minutely 
described  by  Albinus;  but  Sabatier  says,  with  good  sense,  that 
he  cannot  distinguish  them,  so  as  to  describe  them  accurately; 
and  he  might  have  added,  that  there  was  not  the  shadow  of  a 


180  MUSCLES  OF  THE  ARM,  &1C. 

motive  for  wasting  time  in  so  trivial  an  employment  as  counting 
the  bundles. 

It  arises  from  the  two  costae,  the  base  and  all  the  internal 
surface  of  the  scapula.  And  indeed  it  is  to  favour  this  origin 
that  the  inner  surface  of  the  scapula  is  full  of  little  risings  and 
hollows,  to  every  one  of  which  the  muscle  adheres  closely. 
Just  under  the  coracoid  process,  is  the  only  part  from  whence 
it  does  not  arise.  That  little  space  is  filled  up  with  cellular 
substance. 

Its  alternately  tendinous  and  fleshy  fibres  are  so  rooted  in 
the  scapula,  and  so  attached  to  its  risings  and  depressions,  that 
it  is  difficultly  cleaned  away  from  the  bone. 

The  tendon  and  upper  edge  of  the  muscle  is  almost  conti- 
nuous with  the  supra  spinatus ; but  from  the  manner  of  its  in- 
sertion, its  effect  is  very  opposite  from  that  of  the  supra  spina- 
tus, for  it  goes  round  the  os  humeri  to  its  insertion,  and  it  is 
fixed  to  the  lesser  tuberosity,  therefore  it  both  pulls  the  arm 
backwards  and  downwards,  and  performs  the  rotation  like  the 
teres  major,  and  latissimus  dorsi.  It  is  also  like  all  the  other 
tendons,  attached  to  the  capsule,  so  as  to  prevent  its  being 
caught ; and  it  is  particularly  useful  by  strengthening  the  shoul- 
der-joint. 

OF  THE  MOTIONS  OF  THE  HUMERUS. 

Having  thus  described  all  the  muscles  which  move  this  bone, 
I shall  review  the  order  in  which  they  are  arranged,  and  mark 
their  place  and  effects. 

To  distinguish  clearly  the  function  of  each  muscle,  we  have 
but  to  mark  the  point  to  w'hich  it  is  attached. 

1.  Those  implanted  above  the  head  of  the  bone  must  raise 
the  arm.  Now  the  supra  spinatus,  infra  spinatus,  and  teres 
minor,  are  implanted  into  the  great  tubercle,  and  raise  the  arm ; 
and  the  deltoides  is  implanted  in  the  same  direction,  and  still 
lower,  so  that  it  performs  the  same  action  with  a still  greater 
degree  of  power. 

2.  There  is  implanted  into  the  opposite,  or  lower  part  of 
the  head,  the  subscapularis,  which,  of  course,  draws  the  arm 
directly  downwards  and  backwards. 

3.  There  is  implanted  into  the  outer  edge  of  the  bicipital 
groove,  the  pectoralis  major,  and  also  the  coraco-brachialis, 
which  comes  in  the  same  direction ; and  these  two  pull  the 
arm  inwards,  towards  the  side  and  forwards. 

4.  There  are  inserted  into  the  inside,  or  lower  side  of  the 
groove,  the  latissimus  dorsi,  and  teres  major,  both  of  which  pul! 


181 


MUSCLES  OF  THE  ARM,  &C. 

the  arm  directly  backwards,  as  they  bend  under  the  arm,  to 
reach  their  insertion.  They  also  roll  the  palm  inwards  and 
backwards.  And  it  is  easy  to  observe  in  what  succession  those 
muscles  must  act,  to  describe  the  circular  and  rotary  motions 
of  the  arm. 

Joints  are  more  strengthened  by  the  origin  and  insertion  of 
muscles  around  them,  than  by  elastic  ligaments,  which  yield 
or  tear;  whereas  the  muscles,  having  a living  power,  re-act 
against  any  separating  force.  They  contract,  or,  in  other  words, 
they  are  strong  in  proportion  to  the  violence  that  the  joint  suf- 
fers. Thus,  in  the  shoulder  the  capsule  is  so  lax,  that  there  is 
a mechanical  contrivance  to  prevent  its  being  checked  in  the 
joint,  and  it  is  moreover  so  weak,  that,  independent  of  its 
yielding  easily,  it  is  also  very  easily  torn  ; but  these  muscles 
surround  the  joint  so  fairly,  ttiat  their  strength  and  their  tendi- 
nous connections  with  the  head  of  the  bone  are  more  than  a 
compensation  for  the  looseness  of  its  capsular  ligament.  Were 
not  the  muscles  thus  closely  attached,  the  shoulders  would  be 
very  often  displaced,  the  glenoid  cavity  is  so  superficial,  and 
the  bursa  so  lax ; and  surely  it  is  for  some  such  purpose,  that 
the  muscles  are  planted  so  closely  round  the  head  ; for  when 
they  are  implanted  at  a distance  from  the  centre,  as  one  mus- 
cle, the  deltoid,  is,  or  as  the  biceps  and  triceps  of  the  arm,  or 
the  ham-strings,  or  tendo  Achillis,  the  power  is  much  increased. 
Here,  in  the  muscles  arising  from  the  scapula,  power  is  sacri- 
ficed to  the  firmness  of  the  joint,  and  they  are  all  implanted 
closely  round  the  head  of  the  bone. 

The  connection  of  the  bones  in  this  joint  is  in  a manner 
formed  by  these  muscles,  for  the  supra  spinatus,  infra  spinatus, 
teres  major  and  minor,  and  the  subscapularis,  surround  the 
joint  very  closely,  cover  the  joint  with  their  flat  tendons,  and 
so  thicken  the  capsule,  and  increase  its  strength. 

The  muscles  of  the  fore-arm  are  only  four,  the  biceps  and 
BRACHiALis  for  bending,  and  the  triceps  and  anconaius  for 
extending. 

LXXVIII.  Biceps  erachii  flexor  is  universally  named 
BICEPS,  from  its  having  two  very  distinct  heads.  It  is  an  ex- 
ceedingly thick  and  strong  muscle,  for  when  it  contracts,  we 
leel  it  almost  like  a hard  firm  ball  upon  the  forepart  of  the 
arm,  and  at  the  upper  and  most  conspicuous  part  of  this  ball 
is  the  union  of  the  two  heads. 

The  larger  and  thicker  head  arises  from  the  coracoid  pro- 
cess, by  a tendon  which  extends  three  inches  along  the  forepart 
of  the  muscle,  in  the  form  of  an  aponeurosis,  but  at  the  back 
part  the  tendon  is  short,  and  the  muscle  is  attached  there  to 
the  fleshy  belly  of  the  coraco-brachialis. 


182 


MUSCLES  OF  THE  ARM,  &G. 

The  second,  or  long  head,  arises  from  the  edge  of  the  gle- 
noid cavity,  at  its  upper  part ; it  is  exceedingly  small  and  ten- 
dinous, and  this  long  tendon  runs  down  in  its  proper  groove, 
till  about  the  third  part  down  the  humerus  the  two  heads  meet. 
And  though  below  this  it  is  but  one  fleshy  belly,  yet  here,  as 
in  other  muscles,  the  common  division  betwixt  its  two  origins 
may  be  still  observed.* 

It  is  earlier  tendinous  at  the  forepart  and  outer  side;  the 
tendon  here  sends  off  that  aponeurotic  expansion  which  covers 
all  the  arm  below,  and  encloses  the  muscles  as  in  a sheath. 
The  tendon,  at  first  flat  and  large,  becomes  gradually  smaller 
and  rounder  ; it  turns  a little  in  its  descent,  so  as  to  lay  one 
flat  edge  to  the  radius,  and  another  to  the  ulna  ; and  it  is  at 
last  implanted  into  that  round  tubercle,  which  is  on  the  forepart 
of  the  radius  a little  below  its  neck  ; but  it  has  also  an  insertion 
into  the  fascia  of  the  fore-arm. 

The  great  use  of  the  biceps  is  to  bend  the  fore-arm  with 
great  strength.  But  as  it  is  inserted  into  the  tubercle  of  the 
radius,  when  the  arm  and  hand  are  turned  downwards,  it,  by 
acting,  will  pull  them  upwards,  {i.  e.)  it  will  assist  the  supinators. 
Since  both  its  heads  are  from  the  scapula,  it  will  occasionally 
move  the  humerus,  as  well  as  the  fore-arm. 

LXXIX.  The  BRACHiALis  intjbrnus  lies  immediately  un- 
der the  biceps,  and  is  a very  strong  fleshy  muscle  for  assisting 
the  biceps  in  bending  the  arm.  It  is  called  brachialis,  from 
its  origin  in  the  fore-arm,  and  internus,  from  its  being  within 
the  biceps. 

It  arises  from  two-thirds  of  the  os  humeri  at  its  forepart,  by 
a sort  of  forked  head  ; for  it  comes  down  from  each  side  of  the 
deltoid.  It  continues  its  attachment  all  the  way  down  the  fore- 
part of  the  humerus,  to  within  an  inch  of  the  joint.  It  is  very 
thick,  fleshy,  and  strong  ; it  is  tendinous  for  about  two  inches 
in  its  forepart ; and  is  inserted  by  a flat  strong  tendon  into  the 
coronoid  process  of  the  ulna. 

Other  uses  are  ascribed  to  it,  as  the  lifting  up  the  capsule  to 
prevent  its  being  pinched.  But  the  chief  use  of  it  is  to  bend 
the  fore-arm.  In  a strong  man,  it  is  exceedingly  thick,  and  its 
edge  projects  from  under  the  edge  of  the  biceps,  and  is  seen 
in  the  lateral  view. 

LXXX.  Triceps  extensor. — Upon  the  back  part  of  the 
arm  three  muscles  have  been  described  : the  extensor  longus, 
the  extensor  brevis,  and  the  brachialis  externus ; but  there  is, 
in  fact,  only  one  three-headed  muscle. 

* It  is  not  uncommon  to  find  a third  head  to  this  muscle,  which  takes  an  origin  (rom  the 
forepart  of  the  humerus. 


18S 


MUSCLES  OF  THE  ARM,  &C. 

The  longest  head  of  this  muscle  is  in  the  middle.  It  arises 
by  a flat  tendon  ; from  an  inch  of  tbe  edge  of  the  scapula  un- 
der the  neck,  and  a little  way  from  tbe  origin  of  the  long  head 
of  the  biceps  ; and  it  is  under  this  head  that  the  tendon  of  the 
teres  major  passes  to  its  insertion. 

The  second  head  is  on  tbe  outside  of  the  arm,  next  in  length 
to  this.  It  arises  from  the  arm-bone  under  the  great  tuber, 
and  just  below  the  insertion  of  the  teres  minor.  The  long 
and  second  heads  meet  about  the  middle  of  the  humerus. 

The  third,  or  internal  head,  is  the  shortest  of  all.  It  begins 
at  the  inner  side  of  the  humerus,  just  under  the  insertion  of 
the  teres  major  ; and  it  arises  from  the  inner  part  of  the  hume- 
rus, all  the  way  down,  and  joins  just  where  the  second  head 
joins  (z.  e.)  about  the  middle.  All  these  heads  still  continue 
adhering  to  the  humerus  (as  the  brachialis  does  on  the  fore- 
side,) quite  down  to  within  an  inch  of  the  joint,  and  then  a 
strong  thick  tendon  is  formed,  by  which  it  is  implanted  strongly 
in  the  projecting  heel  of  the  ulna,  named  olecranon,  by  which 
projection  of  the  bone  the  muscle  has  great  power,  and  the 
power  is  increased  by  an  increased  length  of  the  process  in  dogs, 
and  other  animals  which  run  or  bound. 

The  whole  forms  a very  thick  and  powerful  muscle,  which 
covers  and  embraces  all  the  back  part  of  the  arm  ; and  its  use 
is  too  simple  to  admit  of  any  farther  explanation,  than  just  to 
say  that  it  extends  the  hinge-joint  of  the  elbow  with  great 
power  ; and  that  by  its  long  head  it  may  assist  also  to  bend 
the  arm-bone  outwards  and  backwards. 

Besides  bones,  there  is  also  another  source  of  attachment 
for  muscles,  that  is,  the  tendinous  expansions  : for  the  expan- 
sions, which  go  on  the  surface  like  sheaths,  also  dive  betwixt 
the  muscles,  and  form  septa,  or  partitions,  from  which  their 
fibres  arise. 

One  tendinous  expansion  begins  from  the  clavicle  and  acro- 
mion process,  or  rather  comes  down  from  the  neck  : it  is  then 
strengthened  by  the  tendon  of  the  deltoid  muscle  ; it  descends, 
covering  all  the  arm  ; and  before  it  goes  down  over  the  fore- 
arm, it  is  again  reinforced  chiefly  by  the  biceps,  but  also  by  the 
tendon  of  the  triceps  extensor.  One  remarkable  process,  or 
partition  of  this  general  fascia,  is  sent  in  from  tbe  sheath  to  be 
fixed  to  the  outside  of  the  humerus,  all  the  way  down  to  the 
ridge  of  the  outer  condyle.  Another  partition  goes  down,  in 
like  manner,  to  the  inner  condyle,  along  the  ridge  which  leads 
to  it ; then  the  fascia,  taking  a firm  hold  on  the  condyles,  is 
greatly  strengthened  about  the  elbow,  and  goes  over  the  fore- 
arm, enelosing  its  muscles  in  a very  firm  and  close  sheath  ; and 


184  MUSCLES  OF  THE  ARM,  &£C. 

it  sends  partitions  down  among  the  several  layers  of  muscles  ii< 
the  fore  arm,  which  gives  each  of  them  a firm  hold. 

LXXXI.  The  anconjEus  is  a small  triangular  muscle,  pla- 
ced on  the  back  part  of  the  elbow.  It  arises  from  the  ridge 
and  from  the  external  condyle  of  the  humerus,  by  a thick, 
strong,  and  short  tendon.  From  this  it  becomes  fleshy,  and 
after  running  about  three  inches  obliquely  backwards,  it  is  in- 
serted by  its  oblique  fleshy  fibres  into  the  outer  part  of  the  ridge 
of  the  ulna. 

It  is  manifestly  designed  for  the  extension  of  the  fore-arm. 
and  has  only  that  one  simple  action. 


MUSCLES  OF  THE  FORE-ABM,  CARPUS,  AND  FINGERS.  " 

The  whole  fore-arm  is  covered  with  a mass  of  muscles  of 
great  strength,  and  so  numerous  and  intricate,  with  a catalogue 
of  names  so  difficult,  and  so  distracting,  that  they  should  be  ar- 
ranged and  classed  with  much  care,  explaining  to  the  student 
the  reason  and  value  of  their  names,  and  the  place  and  effect 
of  each  class. 

The  fore-arm  is  covered  with  a fascia,  or  strong  tendinous 
web,  which,  like  that  which  covers  the  temporal  muscle,  gives 
both  origin  and  strength  to  the  muscles  which  lie  under  it, 
which  divides  the  several  layers  one  from  another,  and  helps 
them  in  their  strong  actions,  with  that  kind  of  support  which 
workmen  feel  in  binding  their  arms  with  thongs.  This  fascia 
is  said  to  proceed  from  the  small  tendon  of  the  biceps  muscle,  ^ 
though  that  were  but  a slender  origin  for  so  great  a web  of  ten-  S 
don,  which  not  only  covers  the  surface  of  the  muscles,  but  ^ 
enters  among  their  layers.  This  fascia  really  begins  in  the  ^ ; 
shoulder,  and  has  an  addition  and  an  increase  of  strength  from 
every  point  of  bone  ; it  is  assisted  by  each  tendon,  because  the 
tendons  and  fascia  are  of  one  nature  over  all  the  body,  and  its  ;n 
connection  with  the  tendon  of  the  biceps  is  quite  of  another  * 
kind  from  that  which  has  been  supposed.  I would  not  allow 
that  the  biceps  tendon  expands  into  the  fascia,  but  rather  that 
the  web  receives  the  biceps  tendon,  W'hich  is  implanted  into  it, 
and  for  this  wise  purpose,  that  when  the  fore-arm  is  to  strike, 
or  the  hand  to  grasp,  the  biceps  first  moves,  and  by  making  the 
fascia  tense,  prepares  the  fore-arm  for  those  voilent  actions 
which  are  to  ensue.  Thus,  it  may  be  defined,  a web  of  thin 
but  strong  tendon,  which  covers  all  the  muscles  of  the  fore-arm, 
makes  the  surface  before  dissection  firm  and  smooth,  sends 
down  partitions  which  are  fixed  into  the  ridges  of  the  radius  j 
and  ulna,  enabling  those  bones  to  give  a broader  origin  to  the 


aiUSCLES  OF  THE  ARM,  &C.  185 

muscles,  establishing  a strong  connection  among  the  several 
layers,  and  making  the  dissection  more  difficult. 

The  motions  to  be  performed  by  the  muscles  which  lie  upon 
the  fore-arm  are  these  three  ; to  roll  the  hand,  to  bend  the 
wrist,  to  bend  the  fingers. 

1.  The  turning  of  the  hand,  which  is  performed  by  rolling 
the  radius  on  the  ulna,  is  named  pronation  and  supination. 
When  we  turn  the  palm  down,  it  is  said  to  be  prone  ; when 
we  turn  the  palm  upwards,  it  is  supine.  This  is  pronation  and 
supination.  The  muscles  which  perform  these  motions  are  the 
PRONATOKS  and  the  supinators,  and  the  motion  itself  is  best 
exemplified  in  the  turning  a key  in  a lock,  or  in  the  guards  of 
fencing,  which  are  formed  by  a continual  play  of  the  radius 
upon  the  ulna,  carrying  the  wrist  round  in  the  half  circle. 

2.  The  wrist  is  called  the  carpus,  and  therefore  those  mus- 
cles which  serve  for  bending  or  extending  the  wrist  are  the 
FLEXORS  and  extensors  of  the  carpus. 

3.  The  bending  and  extending  of  the  fingers  cannot  be  mis- 
taken, and  therefore  the  flexors  and  extensors  of  the  fingers 
need  not  be  explained. 

These  muscles  are  denominated  from  their  uses  chiefly ; but 
if  two  muscles  perform  one  motion,  they  may  be  distinguished 
by  some  accident  of  their  situation  or  form.  And  thus,  if  there 
be  two  benders  of  the  fingers,  one  above  the  other,  they  are 
named  FLEXOR  sublimis,  and  flexor  puofunous,  (i.  e.)  the 
the  superficial  and  deep  flexors.  If  there  be  two  flexors  of  the 
carpus,  one  is  named  flexor  radialis  carpi,  by  its  running 
along  the  radius,  the  other  flexor  ulnaris’ carpi,  from  pass- 
ing in  the  course  of  the  ulna.  And  if  there  be  two  pronators, 
one  may  be  distinguished  pronator  teres,  from  its  round  shape, 
the  other  pronator  quadratus,  from  its  square  form.  And  this, 
I trust,  will  serve  as  a key  to  what  is  found  to  be  a source  of 
inextricable  confusion. 

It  will  be  easy  to  make  the  origins  and  insertions  still  more 
simple  than  the  names ; for  all  the  muscles  arise  from  tw'O 
points,  and  have  but  two  uses. 

This  assertion  shall  be  afterwards  qualified  with  a few  excep-i 
tions ; but  at  present  it  shall  stand  for  the  rule  of  our  demon- 
stration ; for  all  the  muscles  arise  from  tw'o  points,  the  external 
and  internal  condyle.  The  internal  condyle  is  the  longer  one, 
and  gives  most  po-wer  : more  power  is  required  for  bending, 
grasping,  and  turning  the  hand  inwards ; therefore  alt  the  mus- 
cles which  bend  the  hand,  all  the  muscles  which  bend  the  lin- 
gers, and  the  principal  pronator,  or  that  muscle  which  turns  the 
palm  downwards,  arise  from  the  internal  condyle. 

The  external  condyle  is  shorter;  it  gives  less  power;  there 

VOL.  I.  A a 


186 


MUSCLES  OF  THE  ARM,  &C. 


is  little  resistance  to  opening  the  hand  and  little  power  is  re- 
quired in  extending  the  fingers ; and  so  all  the  muscles  whick 
extend  the  wrist  or  the  fingers,  or  roll  the  hand  outwards  to  turn 
it  supine,  arise  from  the  external  cond}’le.  So  that  when  we 
hear  a pronator  or  a flexor  named,  we  know  that  the  origin 
must  be  the  internal  condyle,  and  the  insertion  is  expressed  by 
the  name.  Thus  a pronator  radii  goes  to  the  radius  ; a flexor 
carpi  goes  to  the  wrist : a flexor  digitorum  goes  to  the  fingers; 
and  a flexor  pollicis  goes  to  the  thumb  : and  they  all  issue  from 
the  inner  condyle  as  from  a centre. 

And,  again,  when  a supinator  or  extensor  is  named,  we  know 
where  to  look  for  it ; for  they  also  go  out  from  one  common 
point,  the  external  condyle  ; and  the  supinator  radii  goes  to 
the  radius  ; the  extensor  carpi  goes  to  the  wrist;  tlie  extensor 
pollicis  goes  to  the  thumb ; and  the  extensor  indicis  to  the 
fore  finger. 


FLEXORS. 


The  MUSCLES  closing  and  bending  the  hand  arise  from  the 
internal  condyle.  They  are. 

The  PRONATOR  TERES,  rolling  the  radius  inward. 

PALMARIS  LONGUS, 

FLEXOR  CARPI  RADIALIS, 

ULNARIS,  ) 

DIGITORUM  SUBLIMIS,  ^ 

PROFUNDUS,  > 


bending  the  wrist. 


bending  the 


L<  NGUS  pollicis. 


and  thumb. 


fingen? 


And,  lastly^,  the  pronator  quadratus,  which  is  the  single 
muscle  out  of  that  schemd  which  I have  proposed.* 

LXXXII.  The  pronator  teres  radii  is  of  the  outermost 
layer  of  muscles,  is  small  and  round  ; named  pronator  from  its 


* Mr.  Cliarles  Bel)  in  liis  Lecture,  varies  this  arranvenient.  He  observes  that  a kind  of 
artificial  memory  of  the  muscles  of  the  fore-arm  may  he  had  by  arranging  them  in  numbers; 
for  example,  if  we  take  the  bicep.s  flexor  as  supinator  in  this  instance,  which  it  truly  is,  and 
the  mass  of  the  flexor  muscles  as  one  great  pronator,  for  such  is  their  conjoint  operation,  the® 
the  muscles  go  in  threes — thus : 

For  the  motion  of  the  wrist,  three  flexors,  the  ulnaris,  radialis,  and  medius,  commonly 
called  palmaris  longus. — Three  extensors,  ulnaiis,  radialis  longior,  and  brevior. — Three 
pronators,  the  teres,  quadratus,  and  the  mass  of  flexor  muscles. — Three  supinators,  the 
supinator  longus,  brevis  and  biceps  cubiti.  There  are  three  extensors  of  the  fingers,  extensor 
communis  digitorum,  extensor  prirai  digiti,  extensor  minimi  digiti.— Three  extensors  of  the 
thumb,  extensor  primus,  secundus,  and  tertius. — 'Three  flexors  of  the  fingers  and  thumb, 
flexor  digitorum  sublimis,  flexor  digitorum  profundus,  flexor  pollicis  longus.  In  the  arrange- 
ment of  the  muscles  of  the  fore-arm,  it  is  correct  to  say  that  the  flexors  arise  from  the  inner 
condyle,  and  the  extensors  from  the  outer  condyle ; but  the  supinators  and  pronators  are  tet- 
ter distinguished  by  their  insertion : — thus,  all  muscles  inserted  into  the  radius  turn  the  wrist, 
and  thus  the  supinator  longus,  the  supinator  brevis,  the  pronator  teres,  the  pronator  quadia- 
tiis,  and  tlie  biceps,  are  employed  in  turning  tlie  hand. 


187 


MUSCLES  OF  THE  ARM,  fec. 

office  of  turning  the  radiusi,  and  teres  from  its  shape,  or  rather 
to  distino-uish  it  from  the  pronator  quadratus,  which  is  a short 
square  muscle,  and  which  lies  deep,  being  laid  flat  upon  the 
naked  bones. 

The  pronator  teres  arises  chiefly  from  the  internal  condyle 
of  the  humerus,  at  its  lower  and  forepart.  It  has  a second 
origin  from  the  coronoid  process  of  the  ulna ; these  form  two 
portions,  betwixt  which  passes  the  radial  nerve.  The  muscle 
thus  formed  is  conical,  is  gradually  smaller  from  above  down- 
wards, is  chiefly  fleshy,  but  is  also  a little  tendinous,  both  at  its 
origin  and  at  its  insertion  ; and  stretches  obliquely  across  the 
fore-arm,  passing  over  the  other  muscles  to  be  inserted  in  the 
outer  ridge  of  the  radius,  about  the  middle  of  its  length. 

Its  use  is  to  turn  the  hand  downwards,  by  turning  the  radius; 
and  it  will  also,  in  strong  actions,  be  brought  to  bend  the  fore- 
arm on  the  arm,  or  the  reverse,  when  the  fore-arm  is  fixed, 
and  we  are  to  raise  the  trunk  by  holding  with  the  hands. 

LXXXIII.  The  palmaris  po.vGtJS  is  a long  thin  muscle, 
which,  although  it  seems  to  have  another  use  in  its  expansion 
into  the  aponeurosis,  yet  is  truly,  by  insertion  into  the  annular 
ligament  of  the  wrist,  a flexor  of  the  wrist,  and,  in  some  de- 
gree, a pronator  of  the  radius. 

It  arises  from  the  internal  condyle  of  the  os  humeri,  and  is 
the  first  of  five  muscles  which  have  one  common  tendon  going 
out,  like  radii,  from  one  common  centre,  viz.  the  palmaris ; the 
flexor  radialis  ; the  flexor  ulnaris  ; the  flexor  digitorum  subli- 
mis  ; the  flexor  digitorum  profundus. 

The  palmaris  longus  arises  from  the  inner  condyle  of  the  os 
humeri,  and  also  from  the  intermuscular  tendon,  which  joins  it 
with  the  flexor  radialis  and  flexor  digitorum  sublimis,  and  from 
the  internal  surface  of  the  common  sheath.  Its  fleshy  belly  is 
but  two  inches  and  a half  or  three  inches  in  length ; and  its 
long  slender  tendon  descends  along  the  middle  of  the  fore-arm 
to  be  inserted  into  the  forepart  of  the  annular  ligament  of  the 
wrist,  just  under  the  root  of  the  thumb.  This  tendon  seems  to 
give  rise  to  the  very  strong  thick  aponeurosis  of  the  palm  of  the 
hand,  (under  which  all  the  muscles  of  the  hand  run,  and  which 
conceals  the  arch  of  blood-vessels,  and  protects  them,)  thence 
the  muscle  has  its  name.  But  it  is  a very  common  mistake  to 
think,  that  because  tendons  are  fixed  to  the  sheaths,  the  sheaths 
are  only  productions  of  the  tendons ; whereas  the  sheaths  do 
truly  arise  from  bones.  The  fascia,  which  the  deltoldes  is 
thought  to  fort»y  arises  from  the  acromion  and  clavicle ; and 
the  fascia,  which  the  biceps  is  thought  to  produce,  arises  from 
the  condyles  of  the  humerus ; and  that  great  sheath  of  tendon 
which  is  made  tense  by  the  musculus  fascielis  of  the  thigh,  does 


188 


MUSCLES  OF  THE  ARM,  &tC. 

not  arise  from  that  muscle,  but  coi^es  down  from  the  spine  of 
the  ilium,  strengthened  by  expansions  from  the  oblique  mus- 
cles of  the  abdomen  ; in  the  present  instance,  we  have  the 
clearest  proof  of  fascia  being  derived  from  some  other  source 
than  the  tendons,  for  sometimes  the  palmaris  muscle  is  want- 
ing, when  still  the  tendinous  expansion  is  found,  and  some  pre- 
tend to  say,  that  the  expansion  is  wanting  wheruthe  muscle  is 
found.  The  aponeurosis,  which  covers  the  palm,  is  like  the 
palm  itself,  of  a triangular  figure;  it  begins  from  the  small  ten- 
don of  the  palmaris  longus,  and  gradually  expands,  covering 
the  palm  down  to  the  small  ends  of  the  metacarpal  bones.  Its 
fibres  expand  in  form  of  rays;  and  towards  the  end  there  are 
cross  bands  which  hold  them  together,  and  make  them  stronger; 
but  it  does  not  cover  the  two  outer  metacarpa.1  bones,  (the 
metacarpal  of  the  fore  finger,  or  of  the  little-finger,)  or  it  only 
covers  them  with  a very  thin  expansion. 

Now  this  palmar  expansion  also  sends  down  perpendicular 
divisions,  which  take  hold  on  the  edges  of  the  metacarpal 
bones:  and  thus  there  being  a perpendicular  division  to  each 
edge  of  each  metacarpal  bone,  there  are  eight  in  all,  which 
form  canals  for  the  tendons  of  the  fingers,  and  for  the  lumbri- 
eales  muscles.* 

LXXXIV.  The  palmaris  brevis  is  a thin  flat  cutaneous 
muscle,  which  arises  properly  from  the  edge  of  the  palmar 
aponeurosis,  near  to  the  ligament  of  the  wrist ; whence  it 
stretches  across  the  hand  in  thin  fasciculi  of  fibres,  which  are 
at  last  inserted  into  the  os  pisiforme,  and  into  the  skin  and  fat 
on  the  ulnar  edge  of  the  palm.  This  is  the  palmaris  cutaneus 
of  some  authors,  for  which  we  can  find  no  use,  except  of  draw- 
ing in  the  skin  of  the  hand,  and  perhaps  making  the  palmar 
expansion  tense. 

LXXXV.  The  plexor  carpi  radialis  is  a long  thin  mus- 
cle arising  from  the  inner  condyle,  stretching  along  the  middle 
of  the  fore-arm  somewhat  in  the  course  of  the  radius,  and  . is 
one  of  the  five  muscles  which  rise  by  one  common  tendon,'  '' 
and  which  are,  for  some  way,  tied  together. 

It  arises  tendinous  from  the  inner  condyle  ; the  tendon  very 
short  and  thick.  This  tendon  at  its  origin  is  split  into  many 
(seven)  heads,  which  are  interlaced  with  the  heads  of  the  subli- 
mis,  profundus  palmaris,  he. ; consequently  this  muscle  not 
only  arises  from  the  internal  condyle,  but  also  from  the  inter- 
muscular partitions  (as  from  that  betw'ixt  it  and  the  sublimis) : 
it  forms  a long  tendon,  which,  becoming  at  last  very  small  and 

* There  is  a great  irregularity  in  thi''  muscle ; it  is  frequently  wanting,  and  it  is  not  uh- 
cominon  to  find  two.  We  have  found  more  than  once,  that  tlie  tendinous  part  of  the  mus- 
cle was  next  to  the  condyle,  and  the  fleshy  part  connected  with  the  fascia  palmaris. 


MUSCLES  OF  THE  ARM,  &C. 


189 


round,  runs  under  the  annular  ligament : it  runs  in  a gutter 
peculiar  to  itself ; but  in  this  canal  it  is  moveahle,  not  fixed  ; 
it  then  expands  a very  little,  and  is  inserted  into  the  metacar- 
pal bone  of  the  fore-finger,  also  touching  that  which  supports 
the  thumb. 

Its  use  is  chiefly  to  bend  the  wrist  upon  the  radius.  But 
when  we  consider  its  oblique  direction,  it  will  also  be  very 
evident  that  it  must  have  some  effect  in  pronation  ; and  this, 
like  many  of  the  muscles  of  the  fore-arm,  although  designed 
for  a different  purpose,  will  also  have  some  effect  in  bending 
the  fore-arm  at  the  elbow-joint. 

LXXXVI.  The  flexok  carpi  ulnaris  is  a long  muscle, 
much  like  the  former;  but  as  its  coui’se  is  along  the  radius,  or 
upper  edge  of  the  fore-arm,  this  runs  along  the  ulna  or  lower 
edge. 

It  comes  off  tendinous  from  the  inner  condyle  of  the  os  hu- 
meri, by  the  common  tendon  of  all  the  muscles;  it  has  also, 
like  the  pronator  teres,  a second  head,  viz.  from  the  olecra- 
non process  of  the  ulna,  which  arises  fleshy,  and  the  ulnar 
nerve  perforates  betwixt  these  heads.  The  flexor  ulnaris 
passes  all  along  the  flat  side  of  the  ulna,  betwixt  the  edge  of 
the  sublimis  and  the  ridge  of  the  bone  : and  here  it  has  a third 
origin  of  oblique  fibres,  which  come  from  the  edge  of  the  ulna, 
two-thirds  of  its  length.  Its  tendon  begins  early  on  its  upper 
part,  by  which  it  has  somewhat  the  form  of  a penniform  mus- 
cle. It  has  still  a fourth  origin  from  the  inter-muscular  parti- 
tion, which  stands  betwixt  it  and  the  flexor  sublimis;  and  is 
also  attached  to  the  internal  surface  of  the  common  fascia  of 
the  arm.  Its  long  tendon  is  at  last  inserted  into  the  os  pisi- 
forme  at  its  forepart,  where  it  sends  off  a thin  tendinous  ex- 
pansion to  cover  and  strengthen  the  annular  ligament ; and 
also  a thin  expansion  towards  the  side  of  the  little-finger  to 
cover  its  mucles. 

This  is  to  balance  the  flexor  radialis  : acting  together,  they 
bend  the  wrist  with  great  strength  ; and  when  this  muscle  com- 
bines in  action  with  the  extensor  carpi  ulnaris,  they  pull  the 
edge  of  the  hand  sideways. 

LXXXVII.  The  flexor  uigitorum  communis  sublimis, 
is  named  sublimis  from  being  the  more  superficial  of  the  two 
muscles;  perforatus,  from  its  tendon  being  perforated  by 
the  tendon  of  that  which  lies  immediately  below.  It  lies  be- 
twixt the  palmaris  longus  and  flexor  ulnaris  : it  is  a large  fleshy 
muscle ; and  not  only  its  tendons,  but  its  belly  also,  is  divided 
into  four  fasciculi,  corresponding  with  the  fingers  which  it  is 
to  serve. 

It  arises  from  the  internal  condyle,  along  with  the  other 


190 


MUSCLES  OF  THE  ARM,  &C. 

four  muscles;  from  the  ligament  of  the  elbow-joint ; from  the 
coronnid  process  of  the  ulna;  and  fram  the  upper  part  of  the 
radius,  at  the  sharp  ridge.  By  these  origins,  it  becomes  very 
fleshy  and  thick  ; and,  a little  above  the  middle  of  the  fore-arm, 
divides  into  four  fleshy  portions,  each  of  which  ends  in  a 
slender  tendon.  The  tendons  begin  at  the  middle  of  the  fore- 
arm, or  near  the  division,  but  they  continue  to  be  joined  to 
each  other  by  fleshy  fibres  some  way  down  : and  indeed  the 
fleshy  fibres  cease  only  when  it  is  about  to  pass  under  the  an- 
nular ligament  of  the  wrist.  At  this  place,  a cellular  stringy 
tissue  connects  the  tendons  with  each  other,  and  with  the  ten- 
dons of  the  profundus;  but  after  they  have  passed  under  the 
ligament,  they  expand  towards  the  fingers  which  they  are  to 
serve.  They  each  begin  to  be  extended  and  flattened,  and  to 
appear  cleft ; they  pass  by  the  edge  of  the  metacarpal  bones, 
and  escape  from  under  the  palmar  aponeurosis;  and  where  it 
ends,  viz.  at  the  root  of  the  fingers,  a tendinous  sheath  be- 
gins, in  which  these  tendons  continue  to  be  enclosed. 

The  tendons  are  fairly  split  just  opposite  to  the  top  of  the 
first  phalanx ; and  it  is  at  this  point  that  the  tendons  of  the 
deeper  muscle  pass  through  this  splitting.  The  flattened  ten- 
don parts  into  two,  and  its  oppo.site  edges  diverge ; the  back 
edges  meet  behind  the  tendons  of  the  profundus,  and  form  a 
kind  of  sheath  for  them  to  pass  in  ; and  then  they  proceed  for- 
ward along  the  second  phalanx,  into  the  forepart  of  which  they 
are  implanted. 

This  muscle  is  exceedingly  strong : its  chief  office  is  to  bend 
the  second  joint  of  the  fingers  upon  the  first,  and  the  first  upon 
the  metacarpal  bone.  And  in  proportion  to  the  number  of 
joints  that  a muscle  passes  over,  its  offices  must  be  more  nume- 
rous ; for  this  one  not  only  moves  the  fingers  on  the  metacar- 
pus, but  the  hand  upon  the  wrist,  and  even  the  fore-arm  upon 
the  arm. 

LXXXVin.  The  flexor  digitorum  profundus  vel  per- 
FORANS,  has  so  nearly  the  same  origin,  insertion,  and  use,  so 
that  the  description  of  the  last  is  applicable  to  this  muscle  in 
almost  every  point.  This  is  of  a lower  stratum  of  muscles;  it 
lies  deeper,  and  under  the  former,  whence  its  name : and  by 
this  deeper  situation  it  is  excluded  from  any  hold  upon  the  tu- 
bercle of  the  humerus. 

It  arises  from  the  ulna,  beginning  at  the  coronoid  process, 
and  extending  all  along  its  internal  surface,  from  the  whole 
surface  of  the  interosseous  ligament,  from  the  inner  edge  ol 
radius,  and  also,  in  in  some  degree,  from  the  inter-muscular 
membrane,  which  separates  this  from  the  sublimis. 


191 


MUSCLES  OF  THE  ARM,  &C. 

This  muscle  is  small,  we  may  say  compressed  above ; but  it 
grows  pretty  strong  and  fleshy,  tiear  the  middle  of  the  arm  ; it 
divides  above  the  middle  of  the  arm  into  four  portions,  cor- 
responding with  the  four  fingers;  and  it  is  about  the  middle  of 
the  arm  that  the  tendons  begin,  and  continue  to  receive  mus- 
cular fibres  from  behind,  all  down  to  the  ligament  of  the  wrist: 
at  the  wrist,  these  tendons  are  tied  to  each  other,  and  to  the 
tendons  of  the  sublimis,  by  loose  tendinous  and  cellular  fibres. 
They  diverge  from  each  other,  after  passing  under  the  annular 
ligament;  and  going  along  in  the  hollow  of  the  bones,  under 
the  tendons  of  the  sublimis,  they  first  pass  through  the  bridges 
formed  by  the  palmar  aponeurosis,  then  enter  the  sheaths  of  the 
fingers,  and  finally  pass  through  the  perforations  of  the  subli- 
mis, a little  below  the  second  joint  of  the  fingers  : at  this  place 
the  perforating  tendons  are  smaller  and  rounder  for  their  easy 
passage,  and  after  passing,  they  again  expand  and  become  flat. 
They  also,  above  this,  appear  themselves  to  split  in  the  middle 
without  any  evident  purpose  ; they  pass  the  second  phalanx, 
and  are  fixed  into  the  root  of  the  third.  And  every  thing  that 
is  said  of  the  use  of  the  sublimis  may  be  applied  to  this,  only 
that  its  tendons  go  to  the  furthest  joint. 

LXXXIX.  Lumbricales. — I shall  here  describe,  as  a natu- 
ral appendage  of  the  profundus,  the  lumbricales  muscles, 
which  are  four  small  and  round  muscles,  resembling  the  earth- 
worm, in  form  and  size  ; whence  they  have  their  name.  They 
arise  in  the  palm  of  the  hand,  from  the  tendons  of  the  profun- 
dus, and  are  therefore  under  the  sublimis,  and  under  the  pal- 
mar aponeurosis.  They  are  small  muscles,  with  long  and  very 
delicate  tendons.  Their  fleshy  bellies  are  about  the  length  of 
the  metacarpal  bones,  and  their  small  tendons  stretch  over  two 
joints,  to  reach  the  middle  of  the  second  phalanx.  The  first 
lumbricalis  is  larger  than  the  second,  and  the  two  first  larger 
than  the  two  last. 

The  first  arises  from  the  side  of  the  tendon  of  the  fore- 
finger, which  is  next  to  the  radius;  the  others  arise  in  the  forks 
of  the  tendons;  and  though  they  rise  more  from  that  tendon 
which  is  next  the  ulna,  yet  they  have  attachments  to  both. 
Their  tendons  begin  below  the  first  joint  of  each  finger  ; they 
run  very  slender  along  the  first  phalanx,  and  they  gradually 
wind  around  the  bone,  so  that  though  the  muscles  are  in  the 
palm  of  the  hand,  the  tendons  are  implanted  in  the  back  parts 
of  the  fingers,  and  their  final  connection  is  not  with  the  bend- 
ing tendons  of  the  sublimis  and  profundus,  but  with  tendons 
of  the  extensor  digitorum,  and  with  the  tendons  of  the  external 
interossei  muscles,  with  which  they  are  united  by  tendinow^ 

■ breads. 


192 


MUSCLES  OF  THE  ARM,  &C. 

Hence  their  use  is  very  evident;  they  bend  the  first  joint, 
and  extend  the  second ; they  perform  alternately  either  office ; 
when  the  extensors  act,  they  assist  them  by  extending  the 
second  phalanx  or  joint:  when  the  flexors  act,  and  keep  the 
first  and  second  joint  bended,  the  extending  effect  of  these 
smaller  muscles  is  prevented,  and  all  their  contraction  must  be 
directed  so  as  to  affect  the  first  joint  only,  which  they  then 
bend. 

They  are  chiefly  useful  in  performing  the  quick  short  mo- 
tions, and  so  they  are  named  by  Cowper,  the  musculi  fidici- 
iiales,  as  chiefly  useful  in  playing  upon  musical  instruments. 

XC.  The  FLEXOR  LONGUS  poLLicis  is  placed  by  the  side  of 
the  sublirnis,  or  perforatus,  and  lies  under  the  supinator  and 
flexor  carpi  radialis.  It  runs  along  the  inner  side  of  the  radius 
whence  chiefly -it  arises. 

Its  origin  is  from  all  the  internal  face  of  the  radius  down- 
wards, from  the  place  where  the  biceps  is  inserted,  and  from 
the  interrosseous  ligament,  all  the  length  down  to  the  origin  of 
the  pronator  quadratus : nor  does  it  even  stop  here ; for  the 
tendon  continues  to  receive  fleshy  slips  all  the  way  down  to  the 
passage  under  the  ligament  of  the  wrist.  It  has  also  another 
head,  which  arises  from  the  condyle  of  the  humerus,  and  the 
forepart  of  the  ulna ; which  head  is  tendinous,  and  joins  that 
origin  which  comes  from  the  radius. 

The  muscle  becomes  again  tendinous,  very  high,  [i,  e.)  above 
the  middle  of  the  arm  ; and  its  small  tendon  passes  under  the 
annular  ligament,  glides  in  the  hollow  of  the  os  metacarpi  pol- 
licis,  and  separates  the  short  flexor  into  two  heads,  passes  be- 
twixt the  two  cesamoid  bones  in  the  first  joint  of  the  thumb, 
and  running  in  the  tendinous  sheath,  it  reaches  at  last  the  end 
of  the  farthest  bone  of  the  thumb,  to  be  inserted  into  the  very 
point  of  it. 

There  is  sometimes  sent  off  from  the  lower  part  of  the 
muscle  a small  fleshy  slip,  which  joins  its  tendons  to  the  indi- 
cator tendon  of  the  sublirnis. 

Its  uses,  we  conjecture,  are  exactly  as  of  those  of  the  other 
flexors,  to  bend  the  last  phalanx  on  the  first,  the  first  on  the 
metacarpal  bones,  and,  occasionally,  the  wrist  upon  the  radius 
and  ulna. 

XCl.  The  PRONATOR  Q,UADRATus,  SO  named  from  its  shape 
and  lorm,  is  one  of  the  most  simple  in  its  action,  since  it 
serves  but  one  direct  purpose,  viz.  turning  the  radius  upon  the 
ulna. 

It  lies  flat  upon  the  interosseous  ligament  upon  the  forepart 
of  the  arm,  about  two  inches  above  the  wrist;  it  is  nearly 
square,  and  is  about  three  inches  in  length  and  breadth.  Its 


193 


SlUSCLES  OF  THE  ARM,  &C. 

fibres  go  obliquely  across,  betwixt  the  radius  and  ulna.  It  arises 
from  the  edge  of  the  ulna,  adheres  to  the  interosseous  ligament, 
and  goes  to  be  implanted  into  the  edge  of  the  radius ; it 
turns  the  radius  upon  the  ulna.  This  muscle,  and  in  some 
degree  also  the  flexor  pollicis,  are  the  only  muscles  which  do 
not  come  fairly  under  that  arrangement,  by  which  I have  en- 
deavoured to  explain  the  muscles  of  the  fore-arm. 

EXTENSORS. 

The  muscles  which  lie  upon  the  outer  side  of  the  fore-arm, 
the  supinators,  and  the  extensors  of  the  fingers  and  wrist,  all 
arise  from  one  point,  the  external  condyle  of  the  humerus,  and 
are  all  delivered  in  this  list : 

The  EXTENSOR  CARPI  RAOIALIS  LONGIOR, 

The  EXTENSOR  CARPI  RAOIALIS  BREVIOR,  > • , 

mi  , I wrist. 

The  EXTENSOR  CARPI  ULNARIS,  ) 

The  SUPINATOR  LONGUs, — tums  the  palm  upwards. 

The  EXTENSOR  COMMUNIS  DiGiToRUM, — extends  all  the  fingers, 
and  unfolds  the  hand. 

The  EXTENSOR  PRTMI  INTERNODII 
POLLICIS, 

The  EXTENSOR  sECUNDi  INTERNODII  I extend  the  several  joints 

POLLICIS,  I of  the  thumb. 

The  EXTENSOR  TERTII  INTERNODII  | 

POLLICIS,  J 

The  EXTENSOR  PRiMi  DiGiTi  vel  INDICATOR, — extends  the  fore- 
finger. 

The  EXTENSOR  MINIMI  DiGiTi  vel  AURicuLARis, — extends  the 
little-finger. 

All  these  muscles  arise  from  one  point,  the  external  condyle. 
They  all  roll  the  radius  outwards,  or  extend  the  wrist,  or  ex- 
tend the  fingers.  As  the  muscles  which  are  bent,  need  more 
fibres,  and  greater  strength,  they  arise  from  the  internal  con- 
dyle, which  is  the  larger  ; they  lie  in  a deep  hollow,  for  the 
bones  of  the  fore-arm  are  bent  to  receive  them,  and  they  form 
a very  thick  fleshy  cushion : but  the  extensors  requiring  less 
power,  arise  from  the  shorter  process  of  the  outer  condyle,  are 
on  the  convex  side  of  the  arm,  and  are  thin,  having  few  fibres  j 
for  though  there  is  a large  mass  of  flesh  on  the  inner  side  of 
the  arm,  forming  two  big  flexors,  there  is  only  a thin  layer  on 
the  outer  side  of  the  arm,  forming  one  flat  and  weak  exten- 
sor. 

XCII.  Supinator  radii  longus.  This  muscle  forms  the 
very  edge  of  the  fore  arm  : it  arises  by  many  short  tendinous 
fibres,  from  the  ridge  of  the  humerus,  above  the  external  con- 
VOL.  i.  B b 


194 


MUSCLES  OF  THE  ARM,  &C. 

dyle,  which  origin  is  fully  two  inches  in  length  above  the  con- 
dyle. It  also  arises  from  the  intermuscular  membrane ; and, 
as  it  stands  on  the  very  edge  of  the  fore-arm,  it  runs  betwixt 
the  flex(tr  and  extensor  radialis.  It  becomes  thicker  as  it  pas- 
ses the  joint  of  the  humerus,  and  there  gives  a very  peculiar 
form  to  the  arm  : it  then  becomes  smaller,  and  forms  a flat 
tendon,  which  is  quite  naked  of  flesh  I'rom  the  middle  of  the 
radius,  or  a little  below,  down  to  the  wrist.  This  tendon  be- 
comes gradually  smaller,  till  it  reaches  the  wrist,  where  ex- 
panding a little,  it  is  inserted  into  the  styloid  process  of  the 
lower  head  of  the  radius. 

Its  use  is,  perhaps,  chiefly  as  a supinator,  but  it  is  placed  just 
upon  the  edge  of  the  arm  ; it  stands  as  a sort  of  intermedium 
betwixt  the  two  sets  of  muscles ; it  is  fixed,  indeed,  rather  upon 
the  internal  surface  of  the  radius ; but  yet  when  the  supina- 
tion is  complete,  when  the  hand  is  rolled  very  much  outward 
it  will  become  a pronator. 

It  is  at  once  supinator  and  pronator,  and  for  a most  evident 
reason,  a flexor  also  of  the  fore-arm,  since  its  origin  is  at  least 
two  inches  up  the  humerus,  above  the  joint  of  the  elbow. 

XCIII.  The  EXTENSOR  CARPI  RADIALIS  LONGioR,  has  the 
additional  name  of  longior  or  primus,  to  distinguish  it  from  the 
next.  It  is  almost  entirely  covered  with  the  last  muscle,  the 
supinator. 

It  arises  from  the  ridge  of  the  humerus  above  the  external 
condyle  and  just  under  the  origin  of  the  supinator ; it  de- 
scends all  along  the  back  of  the  radius ; and  after  having  be- 
come a thick  fleshy  belly,  it  degenerates  a little  lower  than  the 
middle  of  the  radius,  into  a thin  flat  tendon,  which  becomes 
slender  and  small  as  it  descends  ; and  turning  a little  more  to- 
wards the  back  of  the  radius,  it  then  passes  over  the  wrist,  and 
goes  along  with  the  tendon  of  the  extensor,  under  the  annular 
ligament,  passing  in  a groove  of  the  radius ; at  last  it  is  inserted 
into  the  root  of  the  metacarpal  bone  of  the  fore-finger,  in  that 
edge  next  the  thumb. 

It  is  chiefly  an  extensor  of  the  wrist : in  pronation,  it  pulls 
the  wrist  directly  backwards ; in  supination,  it  moves  the  hand 
sideways.  It  is  also  a pronator,  when  the  hand  is  turned  back 
to  the  greatest  degree  ; and  from  its  origin,  high  upon  the 
arm-bone,  it  is  also  a flexor  of  the  fore-arm. 

XCIV.  Extensor  carpi  radialis  brevior. — This  mus- 
cle is  almost  the  same  in  description,  name,  and  use,  with  the 
former.  It  arises  from  the  external  condyle  ; and  here  a com- 
mon tendon  for  many  muscles  is  formed,  just  as  in  the  internal 
condyle ; for  from  this  point  arise  the  extensor  carpi  radialis 


MUSCLES  OF  THE  ARM,  &C.  195 

brevior,  extensor  digitorum,  extensor  minimi  digiti,  extensoi’ 
oarpi  ulnaris. 

The  extensor  carpi  radialis  brevior  arises  from  the  outer 
condyle  of  the  humerus,  by  the  common  tendon  ; it  also  arises 
from  the  aponeurosis,  wllich  lies  betwixt  the  extensor  digito- 
rum  and  this  ; it  grows  a pretty  large,  fleshy  body,  and  begins, 
like  the  last,  to  be  tendinous  below  the  middle  of  the  radius  ; 
so  that  this  muscle  continues  fleshy  lower  than  the  last  one, 
and  its  tendon  is  also  much  larger  and  thicker ; it  runs  under 
the  annular  ligament,  in  the  same  channel  with  the  extensor 
longior ; it  expands  a little  before  its  insertion,  which  is  into 
the  back  part  of  the  metacarpal  bone  of  the  middle  finger,  a 
little  towards  that  edge  which  is  next  the  radius  : some  little 
fibres  pass  from  this  tendon  to  the  metacarpal  bone  of  the  fore- 
finger. 

All  that  was  said  concerning  the  extensor  longus,  may  be 
said  of  this ; for  all  the  three  last  muscles  lie  so  ambiguously 
on  the  edge  of  the  arm  that  though  they  are  regularly  supina- 
tors and  extensors,  they  become  pronators  and  flexors,  in  cer- 
tain positions  of  the  hand. 

XCV.  Extensor  carpi  ulnaris. — By  the  name  merely  of 
this  muscle  we  know  its  extent  and  course,  its  origin,  insertion, 
and  use. 

It  is  one  of  the  muscles  which  belong  to  the  common  ten- 
don, arising  from  the  external  tubercle  of  the  os  humeri : it 
lies  along  the  ulnar  edge  of  the  arm  ; it  also  arises  from  the  in- 
termuscular membrane,  which  separates  this  from  the  exten- 
sor digitorum  and  the  extensor  digiti  minimi ; and  chiefly  it  is 
attached  to  the  internal  Surface  of  the  common  sheath.  It 
arises  also  from  the  face  and  edge  of  the  ulna,  the  wkole  way 
down  ; its  tendon  begins  in  the  middle  of  its  length,  and  is  ac- 
companied all  down  to  the  wrist  with  feather-like  fleshy  fibres. 

It  is  fixed  into  the  outside  of  the  lower  head  of  the  metacar- 
pal bone  of  the  little-finger. 

Its  use  is  to  extend  the  carpus.  And  it  may  be  now  observ- 
ed, that  when  the  two  extensors  of  the  wrist,  the  radialis  and 
ulnaris  act,  the  hand  is  bent  directly  backwards ; that  when 
the  flexor  radialis  and  extensor  radialis  act  together,  they  bend 
the  thumb  towards  the  radius ; and  that  when  the  flexor  ulna- 
ris and  extensor  ulnaris  act,  they  draw  down  the  ulnar  edge  of 
the  hand. 

XCVI.  Extensor  oigitorum  communis. — ^This  muscle 
corresponds  with  the  sublimis  and  profundus,  and  antagonizes 
them,  and  resembles  them  in  shape  as  in  use.  It  covers  the 
middle  of  the  fore-arm  at  its  back,  and  lies  betwixt  the  exten- 
sor radialis  brevior  and  the  extensor  minimi  digiti. 


196  MUSCLES  OF  THE  ARM,  &C. 

Its  origin  is  chiefly  from  the  outer  condyle,  by  a tendon 
common  to  it,  with  the  extensor  carpi  radialis  brevior ; it 
comes  also  from  the  intermuscular  membrane,  which  separates 
it  on  one  side  from  the  extensor  minimi  digiti,  and  on  the  other 
from  the  extensor  carpi  radialis  brelHor,  and  lastly,  from  the 
back  part  of  the  common  sheath.  It  grows  very  fleshy  and 
thick,  as  it  descends,  and  about  the  middle  of  the  fore-arm  it 
divides  itself  into  three  slips  of  very  equal  size.  But  though 
the  tendons  begin  so  high  they  continue  like  those  of  the  flex- 
ors, to  receive  fleshy  penniform  fibres  all  down,  almost  to  the 
annular  ligament.  These  tendons  are  tied  together  by  a loose 
■web  of  fibres,  and  being  gathered  together  they  pass  under  the 
ligament  in  one  common  and  appropriated  channel.  Baving 
passed  this  ligament  they  diverge  and  grow  flat  and  large.  And 
they  all  have  the  appearance  of  b<*ing  split  by  a perpendicular 
line.  They  are  quite  different  from  the  flexor  tendons  in  this, 
that  they  are  all  tied  to  each  other  by  cross  bands  ; for  a little 
above  the  knuckles,  or  first  joint  of  the  fingers,  all  the  tendons 
are  joined  on  the  back  of  the  hand  by  slips  from  the  little- 
finger  to  the  ring,  from  file  ring  to  the  mid-finger,  and  from 
that  to  the  fore-finger.  So  that  it  seems  to  be  one  ligament 
running  quite  across  the  back  of  the  hand.  It  would  be  fool- 
ish to  describe  them  more  minutely : for  the  cross  bands 
change  their  places,  and  vary  in  every  subject,  and  in  some 
they  are  not  found. 

After  this,  the  tendons  pass  over  the  heads  of  the  metacar- 
pal bones,  along  the  first  phalanx  of  the  fingers,  and  being 
there  joined  by  the  tendons  of  the  interossei  and  lumbricales, 
they  all  together  form  a strong  tendinous  sheath,  which  sur- 
rounds the  back  of  the  fingers. 

Now  it  is  to  be  remembered,  that  this  muscle  serves  only 
for  the  fore,  middle,  and  ring  fingers : that  if  it  moves  the  lit- 
tle-finger, it  is  only  by  a small  slip  of  tendinous  fibres,  which  it 
often  gives  off  at  the  general  divergence,  but  sometimes  not ; 
sometimes  it  gives  one  slip,  sometimes  two,  often  none  at  all. 
And  so  the  little-finger  has  its  proper  extensor  quite  distinct 
from  this. 

The  use  of  the  muscle  is  to  extend  all  the  fingers ; and  when 
they  are  fixed,  it  will  assist  the  extensors  of  the  wrist,  as  in 
striking  backwards  with  the  knuckles. 

XCVIl.  The  EXTENSOR  MiNJMi  DIGITI,  named  also  auri- 
cuLARis,  from  its  turning  up  the  little  finger,  as  in  picking  the 
ear,  should  really  be  described  with  the  last  muscle  ; if  we  see 
the  origin,  course,  and  use  of  this  muscle  exactly  the  same  with 
it,  why  should  we  not  reckon  it  as  a slip  of  the  common  ex- 
tensor, appropriated  to  the  little  finger  ? 


19T 


MUSCLES  OF  THE  ARM,  &C. 

Its  origin  is  from  the  outer  condyle,  along  with  the  other 
tendons.  It  also  adheres  so  closely  both  to  the  tendinous  par- 
titions, and  to  the  internal  surface  of  the  common  fascia,  that 
it  is  not  easily  separated  in  dissection.  It  begins  small,  with  a 
conical  kind  of  head  ; it  gradually  increases  in  size  ; it  is 
pretty  thick  near  the  wrist;  it  adheres  all  along  to  the  com- 
mon extensor  of  the  fingers  ; it  begins  to  be  tendinous  about 
an  inch  above  the  head  of  the  ulna  ; it  continues  to  receive 
fleshy  fibres  down  to  the  annular  ligament ; and  it  passes  under 
the  annular  ligament,  in  a channel  peculiar  to  itself,  which  is 
indeed  the  best  reason  for  making  this  a distinct  muscle. 

This  channel  has  a very  oblique  direction,  and  the  tendon, 
like  all  the  others,  expands  greatly  in  escaping  from  ihe  liga- 
ment of  the  wrist.  It  is  connected  with  the  other  tendons,  in 
the  manner  I have  described.  Close  to  the  wrist,  it  is  con- 
nected with  the  tendon  of  the  ring  finger,  by  a slip  which 
comes  from  it  ; and  at  the  knuckle,  and  below  it,  it  is  again 
connected  with  the  tendons  both  of  the  ring  finger,  and  of  all 
the  others,  by  the  cross  bands  or  expansions. 

Whatever  has  been  said  of  the  use  of  the  last  muscle,  is  to 
be  understood  of  this ; as  its  extending  its  proper  finger,  assist- 
ing the  others  by  its  communicating  band,  and  in  its  extending 
the  wrist,  when  the  fist  is  clenched.  Its  insertion  is  into  the 
back  of  the  second  joint  of  the  little-finger,  along  with  the  in- 
terossei  and  lumbricales.  Its  tendon  has  also  a small  slit;  for 
the  head  of  the  proper  extensor  of  the  little  finger,  and  the 
heads  of  the  common  extensors  of  the  others,  are  inserted  into 
the  top  of  the  second  phalanx,  just  under  the  first  joint.  They 
send  ofl‘  at  the  sides  tendinous  slips,  which,  passing  along  the 
edges  of  the  bones,  do,  in  conjunction  with  the  tendons  of  the 
interossei  and  lumbricales,  form  a split  tendon,  which  meets  by 
two  curves  at  the  foot  of  the  last  bone  of  the  fingers,  to  move 
the  last  joint. 

XCVIII.  The  EXTENSOR  PRIMUS  poLLicis  16  the  shortest  of 
the  three.  It  is  named  by  Albinus,  and  others,  abductor 
LONGUs  ; but  since  every  muscle  that  extends  the  thumb  must 
pull  it  away  from  the  hand,  every  one  of  them  might  be,  with 
equal  propriety,  named  abductors. 

The  extensor  primus  lies  just  on  the  fore  edge  of  the  radius, 
crossing  it  obliquely. 

It  arises  about  the  middle  of  the  fore-arm,  from  the  edge  of 
the  ulna,  which  gives  rise  to  the  interosseous  membrane  itself, 
and  also  from  the  convex  surface  of  the  radius. 

The  fleshy  belly  commonly  divides  itself  into  tw'o  or  three, 
sometimes  four  fleshy  slips,  with  distinct  tendons,  which,  cross- 
ing the  radius  obliquely,  slip  under  the  external  ligament  of 


198 


MUSCLES  OF  THE  ARM,  &C. 

the  carpus,  and  are  implanted  into  the  trapezium  and  the  root 
of  the  first  metacarpal  bone,  or  rather  of  the  first  phalanx  of 
the  thumb,  towards  the  radial  edge,  so  that  its  chief  use  is  to 
extend  the  thumb,  and  to  incline  it  a little  outwards  towards 
the  radius.  It  has  also  frequently  a tendon  inserted  in  the  ab- 
ductor pollicis.  It  must  also,  like  the  extensors  of  the  fingei’s, 
be  an  extensor  of  the  wrist : and  it  evidently  must,  from  its 
oblique  direction,  assist  in  supination. 

XCIX.  The  EXTKNSOR  SECUKDUS  POLLICIS  is  loiiger  than 
the  fii’st.  It  is  named  by  Douglas  the  extensor  secundi  inter- 
nodii  pollicis  ; by  Albinus,  the  extensor  minor  pollicis. 

This  muscle  lies  close  by  the  former.  It  arises  just  below  it 
from  the  same  edge  of  the  radius,  and  from  the  same  surface 
of  the  interosseous  membrane,  it  runs  along  with  it  in  the  same 
bending  course  ; and,  in  short,  it  resembles  it  so  much  that 
Winslow  has  reckoned  it  as  part  of  the  same  muscle. 

Its  origin  is  from  the  edge  of  the  ulna,  the  interosseous 
ligament,  and  the  radius.  Its  small  round  tendon  passes  some- 
times in  a peculiar  channel,  sometimes  with  the  extensor  pri- 
mus. It  goes  over  the  metacarpal  bone  of  the  thumb  ; it  ex- 
pands upon  the  bone  of  the  first  phalanx ; and  it  is  inserted 
just  under  the  second  joint. 

It  extends  the  second  bone  of  the  thumb  upon  the  first ; it 
extends  the  first  bone  also ; and  it  extends  the  wrist,  and,  by 
its  oblique  direction,  contributes  to  supination. 

C.  Extensor  teutius  pollicis. — This  which  bends  the 
third  joint  is  called  in  common  the  extensor  longus  pollicis. 
And  here  is  a third  muscle,  which  in  form,  and  place,  and 
function,  corresponds  w'ith  the  two  former  ones. 

Its  origin  is  from  the  ridge  of  the  ulna,  and  from  the  upper 
face  of  the  interosseous  membrane  ; and  it  is  a longer  muscle 
than  the  others,  for  it  begins  high,  near  the  top  of  the  ulna,  and 
continues  the  whole  way  down  that  bone,  and  is  very  fleshy 
and  thick.  It  is  penniform  all  the  way  down  to  the  ligament 
of  the  wrist ; and  its  small  tendon  passes  the  ligament  in  a pe- 
culiar ring.  This  tendon  appears  split,  like  those  of  the  fin- 
gers ; it  goes  along  the  ulnar  side  of  the  first  bone  of  the  thumb, 
reaches  the  second,  and  is  implanted  there  by  a small  slip  of 
tendon ; and  being  expanded,  it  still  goes  forward,  to  be  in- 
serted once  more  into  the  third  bone  of  the  thumb  at  its  root. 

Its  use  is  evident,  after  describing  the  others.  For  we  have 
only  to  add  another  joint  for  motion.  It  moves  the  last  joint 
of  the  thumb,  then  the  second,  then  its  metacarpal  bone  upon 
the  carpus ; and  if  that  be  held  firm,  it  will  extend  the  carpus ; 
and  it  will,  in  its  turn,  contribute  to  supination,  though  in  a less 
degree  than  the  others. 


199 


MUSCLES  OF  THE  ARM,  &C. 

CL  Indicator. — The  extensor  indicis  proprius  has 
very  nearly  the  same  origin,  and  exactly  the  same  course  Avith 
the  last,  and  lies  by  the  side  of  it. 

Its  origin  is  from  the  ulna,  by  the  side  of  the  extensor  longus 
pollicis.  It  has  also  some  little  attachments  to  the  interosseous 
membrane.  It,  like  the  others,  is  feathered  with  fibres,  in  an 
oblique  direction,  down  to  the  ligament  of  the  aatIsL 

This  muscle  lies  under  the  extensor  communis  digitorum  : 
its  tendon  passes  along  with  the  common  tendon,  through  the 
annular  ligament;  and  near  the  top  of  the  metacarpal  bone, 
or  about  the  place  of  the  common  junctions  of  all  these  ten- 
dons, this  one  joins  with  the  indicator  tendon  of  the  common 
extensor. 

Its  use  is  in  extending  all  the  three  joints  of  the  fore-finger; 
assisting  the  common  extensor  in  pointing  with  that  finger;  in 
acting  independently  of  the  common  extensor;  and  in  helping 
to  extend  the  wrist,  when  the  fingers  are  closed. 

CII.  The  SUPINATOR  BREVIS  is  an  internal  muscle,  Avhich 
forms,  with  the  muscles  of  the  thumb  and  of  the  fore-finger,  a 
kind  of  second  layer ; and  this  one  lies  concealed,  as  much  as 
the  pronator  quadratus  does,  on  the  inner  side  of  the  fore-arm. 
It  is  a short  muscle,  but  very  thick  and  fleshy,  and  of  great 
power. 

It  arises  from  the  outer  condyle  of  the  os  humeri,  and  from 
the  edge  of  the  ulna,  and  from  the  interosseous  ligament : it  is 
then  lapped  over  the  radius,  and  is  inserted  into  its  ridge ; so 
that  this  supinator  brevis  is  very  directly  opposed  to  the  pro- 
nator teres,  the  insertion  of  the  two  muscles  almost  meeting 
on  the  edge  of  the  radius.  It  is  almost  circumscribed  to  one 
use,  that  of  performing  the  rotation  of  the  radius  outwards ; 
but,  perhaps,  it  may  also  have  some  little  effect  in  extending 
the  ulna,  and  of  assisting  the  anconeus. 

MUSCLES  SEATED  ON  THE  HAND. 

Besides  these  muscles  which  bend  and  extend  the  fingers, 
there  are  other  smaller  ones  seated  on  the  hand  itself,  which 
are  chiefly  for  assisting  the  former,  and  for  quicker  motions  j 
but  most  especially  for  the  lateral  motions  of  the  fingers,  and 
which  are  named  adductors,  abductors,  and  flexors, 
Avhen  they  belong  to  the  thumb  and  to  the  little-finger. 

That  they  are  chiefly  useful  in  assisting  and  strengthening 
the  larger  muscles,  is  evident  from  this,  that  much  power 
being  required  for  flexion,  we  find  many  of  these  smaller  mus- 
cles added  in  the  palm  ©f  the  hand ; but  as  there  is  little 


200  MUSCLES  OF  THE  ARM,  &C. 

power  of  extension  needed,  no  more  almost  than  to  balance 
the  power  of  the  flexors,  there  are  no  small  muscles  on  the 
back  of  the  hand,  the  interossei  extern!  excepted,  which  are 
chiefly  useful  in  spreading  the  fingers. 

The  short  muscles  in  the  palm  of  the  hand  are  for  bending 
the  thumb,  the  fore-finger  and  the  little-finger;  and  the  little- 
finger  and  the  thumb  have  each  of  them  tliree  distinct  muscles; 
one  to  pull  the  thumb  away  from  the  hand,  one  to  bend  it, 
and  one  to  pull  it  towards  the  hand,  opposing  it  to  the  rest  of 
the  fingers,  and  so  of  the  little-finger,  which  has  also  three 
muscles. 


ARRANGEMENT  OF  THESE  MUSCLES. 


1.  LUMBRiCALES,  whicli  bend  the  fingers. 

2.  ABDUCTOR  POLLieis,  removing  the  thumb  from  the  fingers. 

carrying  the  thumb  tow’ards 


3. 


4. 


6. 


the  palm,  as  in  grasping. 


the  fore-finger  towards 


I FLEXOR  AND  OPFONENS 

< POLLICIS, 

( ADDUCTOR  POLLICIS, 

S which  carries 

ABDUCTORlND.es, 

C ABDUCTOR  MINIMI  DiGiTi,  i wliicli  bend  the  little-finger, 

< ADDUCTOR  MINIMI  DIGITI,  > and  cariy  it,  like  the  thumb, 
^FLEXOR  MINIMI  DIGITI,  ) outwards  or  inwards. 

f which  are  small  muscles,  lying  betwixt  the 
1 metacarpal  bones,  and  assisting  the  liimbri- 
iNrEROssEi<  bending  the  fingers,  and  perform  the 

(^lateral  motions  of  the  fingers. 

All  the  muscles  of  the  thumb  are  seated  on  the  inside,  to 
form  the  great  ball  of  the  thumb;  and  it  is  not  easy  at  first  to 
conceive  how  muscles  having  so  much  the  same  place  should 
perform  such  opposite  motions ; yet  it  is  easily  explained,  by 
the  slight  variation  of  their  places;  for  the  abductor  arises 
from  the  annular  ligament  near  the  radius,  and  goes  towards; 
the  back  of  the  thumb. 

The  flexors  arise  deeper,  from  the  bones  of  the  carpus,  and 
from  the  inside  of  the  ligament,  and  go  to  the  inside  of  the 
thumb.  The  adductor  arises  from  the  metacarpal  of  the 
mid-finger,  and  goes  to  the  inner  edge  of  the  thumb. 

cm.  The  ABDUCTOR  POLLICIS  is  only  covered  by  the  com- 
mon integuments.  It  begins  a little  tendinous  from  the  out- 
side of  the  annular  ligament,  just  under  the  thumb,  and  by 
some  little  fibres  from  the  trapezium  ; and,  from  the  tendon 
of  the  long  abductor  or  extensor  primus,  it  bends  gradually 
round  the  thumb,  and  is  at  last  inserted  in  the  back  of  the  first 
joint,  just  above  the  head  of  the  metacarpal  bone.  But  it 


201 


MUSCLES  OF  THE  ARM,  &C. 

does  not  stop  here ; for  this  flat  tendon  is  now  expanded  into 
the  form  of  a fascia,  which,  surrounding  the  first  bone  of  the 
thumb,  goes  forward  upon  its  back  part,  quite  to  the  end,  along 
with  the  common  tendon  of  the  extensor.  This  muscle,  like 
the  others,  is  covered  by  a thin  expansion  from  the  tendon  of 
the  palmaris,  as  well  as  by  the  common  integuments. 

Its  only  use  is  to  pull  the  thumb  from  the  fingers,  and  to 
extend  the  second  bone  upon  the  first. 

Albinus  describes  a second  muscle  of  the  same  name, 
having  the  same  course,  origin,  insertion,  and  use : it  also 
arises  from  the  outer  side  of  the  ligament  of  the  wrist,  and  is 
fixed  into  the  side  of  the  thumb,  and  lies  upon  the  inside  of 
the  former  muscle. 

These  two  are  inserted  into  the  first  bone  of  the  thumb  ; but 
the  next  is  inserted  into  the  metacarpal  bone. 

CIV.  The  oppoNENS  poelicis  is  often  called  the  flexor  of 
the  metacarpal  bone  of  the  thumb.  It  is  placed  on  the  inside, 
and  implanted  into  the  side  of  the  thumb  : its  oflBce  is  to  draw 
the  thumb  across  the  other  fingers,  as  in  clenching  the  fist ; 
and  from  its  thus  opposing  the  fingers  it  has  its  name  of  oppo- 
nens. 

It  lies  immediately  under  the  last  described  muscle,  and  is 
like  it  in  all  but  its  insertion. 

It  arises  from  the  trapezium,  and  from  the  ligament  of  the 
wrist.  It  is  inserted  into  the  edge  and  forepart  of  the  meta- 
carpal bone  of  the  thumb : and  its  use  is  to  turn  the  metacar- 
pal bone  upon  its  axis,  and  to  oppose  the  fingers ; or  in  other 
words,  to  bend  the  thumb : for  I can  rmdie  no  distinction. 
Therefore,  this  muscle  and  the  next,  which  lies  close  upon  it, 
may  be  fairly  considered  as  but  two  different  heads  of  one  thick 
short  muscle. 

CV.  The  FLEXOR  BREVIS  polllicis  is  a two-headed  muscle, 
placed  quite  on  the  inside  of  the  thumb,  betwixt  the  fore-finger 
and  the  thumb,  and  extends  obliquely  across  the  two  first  me- 
tacarpal bones.  It  is  divided  into  two  heads  by  the  long  flexor 
of  the  thumb. 

The  edge  of  this  muscle  lies  in  close  contact  with  the  edge 
of  the  last,  or  opponens ; and  indeed  they  may  fairly  be  consi- 
dered as  one  large  muscle  surrounding  the  basis  of  the  thumb. 

One  head  arises  from  the  os  trapezium,  or  base  of  the 
thumb,  and  from  the  ligament  of  the  wrist.  The  other  head 
comes  from  the  os  magnum  and  unciforme,  and  from  the  liga- 
ments which  unite  the  bones  of  the  carpus. 

The  first  head  is  the  smaller  one  : it  terminates  by  a pretty 
considerable  tendon  in  the  first  sesamoid  bone.  The  second 
head  runs  the  same  course ; it  is  implanted  chiefly  in  the  se- 

VOE.  I.  Cc 


202 


MUSCLES  OF  THE  ARM,  &C. 

cond  sesamoid  bone,  and  also  Into  the  edge  of  the  first  bone 
of  the  thumb  close  by  it.  The  second  head  is  exceedingly 
muscular  and  strong : the  heads  are  completely  separated 
from  each  other  by  the  tendon  of  the  flexor  longus  passing 
betwixt  them. 

The  oflice  of  this  muscle  is  to  bend  the  first  joint  upon  the 
second,  and  the  metacarpal  bone  upon  the  carpus  : and  in- 
deed the  office  of  this,  and  of  the  opponens,  is  the  same.  It 
is  in  the  tendons  of  this  double-headed  muscle  that  the  sesa- 
moid bones  are  found. 

CVl.  The  ADDUCTOR  POL.LICIS  arises  from  the  metacarpal 
bone  of  the  middle-finger,  where  it  has  a flat  extended  base. 
It  goes  frjnn  this  directly  across  the  metacarpal  bone  of  the 
fore-finger  to  meet  the  thumb.  It  is  of  a triangular  shape,  and 
flat : its  base  is  at  the  metacarpal  bone  ; its  apex  is  at  the 
thumb  : it  is  inserted  into  the  lower  part  or  root  of  the  first 
phalanx  : its  edge  ranges  with  the  edge  of  the  flexor  brevis  ; 
it  concurs  with  it  in  office ; and  its  more  peculiar  use  is  to 
draw  the  thumb  towards  the  fore-finger,  as  in  pinching. 

Thus  do  these  muscles,  covering  the  root  of  the  thumb, 
form  that  large  ball  of  flesh  which  acts  so  strongly  in  almost 
every  thing  we  do  with  the  hand. 

The  ball  of  the  thumb  is  fairly  surrounded ; it  is  almost  one 
mass,  having  one  office  : but  as  the  deltoldes  will,  in  some 
circumstances,  pull  the  arm  downwards,  some  portions  of  this 
fleshy  mass  pull  the  thumb  outwards  obliquely  ; some  directly 
inwards ; but  the  great  mass  of  muscle  bends  the  thumb,  and 
opposes  it  to  the  hand  : and  as  this  one  muscle  is  to  oppose  the 
whole  hand,  the  baU  of  flesh  is  very  powerful  and  thick. 

The  short  muscles  of  the  little  finger  surround  its  root,  just 
as  those  of  the  thumb  surround  its  ball. 

evil.  The  ABDUCTOR  MINIMI  DiGiTi  is  a thin  fleshy  muscle, 
which  forms  the  cushion  on  the  lower  edge  of  the  hand,  just 
under  the  little  finger.  It  is  an  external  muscle  : it  arises  from 
the  os  pisiforme,  and  metacarpal  bone  of  the  little-finger,  and 
from  the  outer  end  of  the  annular  ligament.  It  is  inserted  la- 
terally into  the  first  bone  of  the  little-finger  ; but  a production 
of  it  still  goes  forward  to  the  second  bone  of  the  little-finger. 

Its  use  is  to  spread  the  little-finger  sideways,  and  perhaps  to 
assist  the  flexors. 

CVIII.  The  FLEXOR  PARVUS  MINIMI  DIGITI  is  a Small  thin 
muscle  which  rises  by  the  side  of  the  last,  and  runs  the  same 
course,  with  nearly  the  same  insertion. 

Its  origin  is  from  the  ligament  of  the  wrist,  and  in  part  from 
the  crooked  process  of  the  unciforme  bone.  Its  use  is  to  bend 
the  little-finger.  And  indeed  the  office  and  place  of  both  is 


208 


MUSCLES  OF  THE  ARM,  &C. 

EO  much  the  same,  that  I have  marked  the  last  as  a flexor; 
the  little  difierence  there  is,  is  only  that  this  performs  a more 
direct  flexion 

CIX.  The  ADDUCTOR  MINIMI  DiGiTi  is  Sometimes  called  the 
metacarpal  of  the  little-finger.  It  lies  immediately  under  the 
the  former  muscle.  Its  origin  is  from  the  hook  of  the  unciforme 
bone,  and  the  adjoining  part  of  the  carpal  ligament. 

It  is  inserted  into  the  outside  of  the  metacarpal  bone  which 
it  reaches  by  turning  round  it.  Its  use  is  to  put  the  little-fin- 
ger antagonist  to  the  others : it  is  to  this  finger  what  the  op- 
ponens  is  to  the  thumb.  It  also,  by  thus  bending  one  bone  of 
the  metacarpus,  affects  the  whole,  increases  the  hollow'  and 
external  convexity  of  the  carpus,  and  forms  what  is  called  Di- 
ogenes’s cup. 

CX.  The  ABDUCTOR  iNDicis  is  a flat  muscle  of  considerable 
breadth,  lying  behind  the  adductor  pollicis,  and  exactly  re- 
sembling it,  being  like  the  second  layer.  It  arises  from  the 
os  trapezium,  and  from  the  first  bone  of  the  thumb  ; and  it  is 
inserted  into  the  back  part  of  the  first  bone  of  the  fore-finger, 
and  pulls  it  towards  the  thumb. 

The  iNTEROssEi  are  situated  betwixt  the  metacarpal 
bones.  They  are  small,  round,  and  neat,  something  like  the 
lumbricales  in  shape  and  size,  and  in  office  resemble  the 
adductors  and  abductors.  Four  are  found  in  the  palm  which 
bend  the  fingers  and  draw  their  edges  a little  towards  the 
thumb ; three  are  found  on  the  back  of  the  hand,  for  ex- 
tending the  fingers ; they  at  the  same  time  perfoi'm  the  lateral 
motions  of  the  fingers. 

CXI.  The  INTEROSSEI  iNTERNi  arise  from  betwixt  the 
metacarpal  bones.  They  are  also  attached  to  the  sides  of 
these  bones.  They  send  their  tendons  twisting  round  the 
sides  to  the  backs  of  these  bones.  And  they  are  inserted 
along  with  the  tendons  of  the  lumbricales  and  extensors,  into 
the  back  of  the  finger.  They  are  thus  flexors  of  the  first 
joint,  and  extensors  of  the  second  joint,  as  the  lumbricales 
are. 

CXII.  The  INTEROSSEI  EXTERNi  are  three  in  number. 
They  arise,  like  the  interni,  from  the  metacarpal  bones  and 
their  interstices,  and  from  the  ligaments  of  the  caipal  bones. 
They  are  peculiar  in  having  each  two  heads,  therefore' 
named  interossei  bicipites.  They  join  their  tendons  to 
those  of  the  extensor  and  lumbricales ; they  have  therefore 
one  common  office  with  them,  that  is,  extending  all  the 
joints  of  the  fingers.  Many  have  chosen  to  describe  the 
origin  and  insertion  w'ith  most  particular  care,  marking  the 
degree  of  obliquity,  and  ascertaining  precisely  their  office, 


204 


MUSCLES  OF  RESPIRATION, 


and  giving  particular  names  to  each,  as  prior  indicis  for  the 
first  external ; all  which  I forbear  mentioning,  because  they 
must  be  more  liable  to  perplex  than  assist  : if  we  but  re- 
member their  common  place  and  office,  it  is  enough.  The 
tendons  of  the  flexor  muscles  bend  round  the  finger,  along 
with  the  interossei  and  lumbricales,  for  a surer  hold ; con- 
sequently the  tendons  of  the  lumbricales,  of  the  interossei 
interni,  of  the  extensors,  and  of  the  interossei  externi, 
meet  upon  the  backs  of  the  fingers,  which  are  by  them 
covered  with  a very  strong  web  of  tendinous  fibres. 


CHAP.  IV. 

MUSCLES  OF  RESPIRATION  ; OR,  OF  THE 
RIBS. 

The  whole  back  is  clothed  with  strong  muscles,  and  all 
its  holes,  irregularities,  and  spines,  are  ci’ossed  with  many 
smaller  ones.  These  muscles  are  related  either  to  the  arm, 
to  the  ribs,  or  to  the  spine,  (i.  e.)  the  vertebrse,  whose  motions 
they  perform  ; and  from  this  we  obtain  an  arrangement  not 
inconsistent  with  the  regular  order  of  their  office,  and  yet 
corresponding  with  the  best  order  of  dissection. 

The  first,  or  uppermost  layer  of  muscles,  viz.  the 
trapezius,  the  rnusculus  patientiae,  the  rhomboides,  the  latis- 
simus  dorsi,  belong  to  the  arm.  The  serrated  muscles  which 
lie  ^next  under  these,  are  the  muscles  of  respiration,  and 
belong  to  the  ribs;  while  the  splenius  and  complexus,  the 
muscles  of  the  neck,  the  longissimus  dorsi,  sacro-lumbalis, 
and  the  quadratus  lumborum,  which  are  muscles  of  the  back, 
and  the  innumerable  smaller  muscles  which  lie  betwixt  the 
vertebrae,  belong  entirely  to  the  spine. 

Respiration  is  indeed  pei'formed  chiefly  by  the  muscles  of 
the  belly,  that  is,  in  ordinary  and  easy  breathing.  In  high 
breathing,  the  difficulty  is  relieved  by  the  co-operation  of  al- 
most all  the  muscles  of  the  trunk,  of  which  there  is  scarcely 
one  that  may  not  assist  in  some  slight  degree.  But  yet  the 
muscles  of  the  abdomen  have  many  other  offices.  And  the 
muscles  of  the  spine,  and  of  the  scapula,  again  belong  pro- 
perly to  the  arm  and  trunk,  and  therefore  I call  those  the 
muscles  of  respiration,  by  which  the  ribs  are  moved  in 


OR,  OF  THE  RIBS- 


205 


breathing,  and  which  have  no  direct  relation  to  almost  any 
other  motion,  but  merely  that  of  the  ribs. 

The  muscles  which  are  appropriated  to  the  ribs,  per- 


forming no  other  motion. 


are. 


1.  The  SERRATUS  POSTICUS 
SUPERIOR, 


POSTICUS, 


C which  comes  from  the  neck, 

< and  lies  fleshy  over  the  ribs, 

( to  pull  them  upwards, 
f which  comes  from  the  lumbar 
2.  The  SERRATUS  INFERIOR J Vertebrae,  and  lies  flat  on  the 

j lower  part  of  the  back,  to 
(^puU  the  ribs  downwards. 
f which  are  twelve  flat  mus- 
{ cles  arising  from  the  trans- 
J verse  process  of  each  ver- 
k The  LEVATORES  cosTARUM,<(  ^ebra,  and  going  down  to 

the  rib  below,  they  raise 
the  ribs. 

which  lie  betwixt  the  ribs, 
and  fill  up  all  the  space  be- 

4.  The  INTERCOSTAL  MUSCLES,<j 

^ raise  the  ribs. 

And  there  may  be  added  to  these,  that  muscle,  which, 
lying  under  the  sternum,  and  within  the  thorax,  is  called 
triangularis  sterni,  and  pulls  the  ribs  downwards. 

CXIII.  The  SERRATUS  SUPERIOR  POSTICUS  lies  flat  upon 
the  side  of  the  neck,  under  the  trapezius  and  rhomboides, 
and  over  the  splenius  and  complexus  muscles.  It  arises  by 
a flat  and  shining  tendon  from  the  spines  of  the  three  lower 
vertebra:  of  the  neck,  and  the  two  uppermost  of  the  back. 
It  goes  obliquely  downwards  under  the  upper  corner  of  the 
scapula,  and  is  inserted  into  the  second,  third,  fourth,  and 
fifth  ribs,  by  three  or  four  neat  fleshy  tongues. 

The  ligamentum  nuchae  is  chiefly  formed  by  the  meeting  of 
the  trapezii  muscles;  but  the  flat  tendons  of  these  upper 
serrated  muscles  help  to  form  it. 

They  are  purely  levators  of  the  ribs ; their  effect  upon  the 
vertebrae,  if  they  have  any,  must  be  very  slight. 

CXIV.  The  SERRATUS  INFERIOR  POSTICUS  is  a very 
broad  thin  muscle,  situated  at  the  lower  part  of  the  back, 
under  the  latissimus  dorsi,  or  over  the  longissimus  dorsi 
muscle. 

It  arises  in  common  with  the  latissimus  dorsi,  from  the 
spines  of  the  two  lower  vertebrae  of  the  back,  and  the  three 
uppermost  vertebrae  of  the  loins.  Their  origin,  like  that  of 
the  latissimus,  is  by  a thin  tendinous  expansion  ; it  soon 
becomes  fleshy,  and,  dividing  into  three,  sometimes  four 


206 


AIUSCLES  OP  RESPIRATION, 


fleshy  strips  or  tongues,  each  of  them  is  inserted  separately 
into  the  ninth,  tenth,  eleventh,  twelfth  lower  ribs,  near  their 
cartilages.  So  that  this  muscle,  spreading  so  wide  out  from 
the  centre  of  motion,  has  vast  power ; for  it  has  the  whole 
length  of  the  rib  as  a lever. 

The  office  of  it  is  to  pull  the  ribs  downwards  and  back- 
wards, the  effect  of  which  must  be  to  compress  the  chest, 
and  in  certain  circumstances  to  turn  the  spine. 

CXV.  The  LEVATOREs  cosTARUM  are  twelve  muscles  on 
each  side,  for  the  direct  purpose  of  raising  the  ribs  ; they  lie 
above  or  upon  the  ribs,  at  their  angles,  and  are  thence 
named,  by  some  supra  costales. 

They  are  almost  a portion  of  the  external  intercostal 
muscles.  The  first  of  the  levators  arises  from  the  transverse 
process  of  the  last  vertebra  of  the  neck,  and  goes  down  to 
be  inserted  into  the  first  rib,  near  its  tuberosity ; and  so  all 
that  follow  arise  from  a transverse  process,  and  go  to  the  rib 
below,  being  very  small  and  tendinous  at  either  end  ; but  the 
tliree  last  levators  arise  from  the  second  process  above  the 
rib  to  which  they  belong : they  pass  one  rib  to  go  into  the  one 
below  it ; they  are  consequently  twice  as  long  as  the  nine 
first  are,  and  are  therefore  named  levatores  costarum 
LONGiOREs,  from  the  ninth  dowmwards. 

Thus,  the  levatores  costarum  are  a succession  of  small  mus- 
cles, arising  from  the  transverse  processes  of  the  vertebrs,  and 
going  to  the  angles  of  the  ribs,  beginning  from  the  last  verte- 
bra of  the  neck,  and  ending  with  tbe  last  but  one  of  the  back. 
They  lie  under  the  longissimus  dorsi,  and  sacro-lumbalis  ; and 
often  they  have  connections  with  these  muscles,  sometimes  very 
close. 

CXVI.  The  iNTERCOSTALES  extemi  run  obliquely  from  the 
ower  edge  of  one  rib,  downward  and  forward,  or  in  a direction 
from  behind  forward,  to  be  inserted  into  the  upper  edge  of  the 
rib  below ; the  muscle  is  not  continued  into  the  space  betwixt 
the  cartilages  of  the  ribs.  The  internal,  again,  are  perfect  be- 
twixt the  cartilages  of  the  ribs,  but  they  proceed  no  further  back 
than  the  angles  of  the  ribs.  They  are  further  different  from 
the  internal  muscles,  inasmuch  as  they  pass  obliquely  back- 
ward and  downward  from  the  margin  of  the  one  rib  to  the 
other. 

These  two  rows  were  thought  to  antagonize  each  other  ; the 
one  to  pull  the  ribs  downwards,  the  other  to  raise  them  ; but  I 
shall  not  stop  to  explain  this,  nor  to  refute  it ; it  is  sufficient  to 
declare  their  true  use,  which  is  (both  external  and  internal)  to 
raise  the  ribs  and  assist  inspiration.* 

^ I remember  many  years  ago,  to  have  beard  Dr.  Monro  explain  tbe  office  of  the  intercos- 


OR,  OF  THE  RIBS. 


201 


The  ninth,  tenth,  eleventh,  and  twelfth  ribs,  have  a freer  mo- 
tion ; and  it  appears  to  me  that  this  is  the  true  use  of  the 
levatores  longiores;  and  for  the  same  reason,  we  find,  that 
from  the  sixth  rib  and  downwards,  there  are  certain  slips  of  the 
internal  intercostals,  which  pass  over  one  rib,  and  go  to  the 
second  below ; and  as  the  levatores  longiores  were  called  supra- 
costales,  these  have  been  named  jnfra-costales,  and  costa- 
rum  DEPKESSORES  PROPRii.  They  were  discovered  by  Verhein, 
and  bear  his  name  ; they  were  explained  as  depressors  of 
the  ribs  by  Haller,  but  they  are  little  different  from  the  inter- 
costals in  form,  and  not  at  all  in  office,  for  they  raise  the  ribs, 
along  w'ith  the  intercostal  muscles. 

CXVIl.  The  TRIANGULARIS  STERNI,  Or  STERNO  COSTALIS,  is  a 
depressor  of  the  ribs;  an  internal  muscle  lying  chiefly  on  the 
inner  face  of  the  sternum,  and  the  cartilages  of  the  ribs.  It  is 
very  generally  considered  as  a triangular  muscle  on  each  side, 
but  some  consider  it  as  three  or  four  muscles,  under  the  title 
of  sterno-costales. 

There  are  generally  four  slips  lying  on  the  cartilages  of  the 
third,  fourth,  fifth,  and  sixth  ribs.  The  lower  portion  of  the 
triangularis  arises  from  the  ensiform  cartilage,  and  is  inserted 
into  the  third  or  fourth  rib ; the  third  arises  from  the  middle 
of  the  sternum,  and  goes  off  from  the  edges  of  that  bone,  to  be 
inserted  into  the  third  rib. 

The  fourth  or  uppermost  portion  is  often  wanting ; it  goes 
off  in  part,  also,  from  the  inner  surface  of  the  sternum,  but  more 
commonly  from  the  third  rib,  and  goes  to  the  second  rib. 

In  a dog  they  are  much  longer  than  in  a man.  Their  office 
is  to  depress  the  ribs ; and  these  portions  are  all  conjoined  at 
their  roots,  which  gives  the  whole  muscle  the  triangular  shape. 

The  true  uses  of  the  intercostales,  subcostales,  and  triangula- 
ris sterni,  have  been  disputed  ; but  if  the  first  rib  be  more  fixed 
than  the  other  ribs,  then  the  intercostals  proceeding  down- 
wards, from  the  first  rib,  must  raise  all  the  thorax ; and  if  the 
sternum  be  more  fixed  than  the  ribs,  then  the  sterno-costales 
muscles  going  upwards  from  the  sternum,  must  pull  down  the 
ribs. 

tal  musrles  by  a diagram,  deducing  from  that  argument,  the  more  powerfol  effect  of  all  nuiS- 
eles  having  oblique  fibres. 


208 


MUSCLES  OF  THE 


CHAP.  V. 

MUSCLES  OF  THE  HEAD,  NECK,  AND  TRUNK. 

The  serratus  superior  posticus  being  raised,  the  splenii  come 
into  view,  and  the  splenii  being  also  liftedj  the  complexus  is  _ 
fully  exposed.  1 

CXVIH.  Splenius. — The  two  splenii  are  so  named  from 
their  lying  like  surgical  splints,  along  the  side  of  the  neck ; 
both  together  they  have  the  appearance  of  the  letter  Y ; the 
complexus  being  seen  betwixt  them  in  the  upper  part  of  the 
angle.  They  lie  immediately  under  the  trapezii,  and  above 
the  complex!. 

Each  splenius  is  a flat  and  broad  muscle,  which  arises  from 
the  spinous  processes  of  the  neck  and  back,  and  is  implanted 
into  the  back  part  of  the  head.  It  arises  from  the  four  upper 
spines  of  the  back,  and  the  five  lower  of  the  neck ; it  parts 
from  its  fellow  at  the  fifth  vertebra  of  the  neck,  so  as  to  show 
in  the  interstice  two  or  three  of  the  uppermost  spines  of  the 
neck,  with  the  upper  part  of  the  complexus  muscle ; each 
splenius  goes  obliquely  outwards  to  be  inserted  into  the  occipi- 
tal ridge,  and  all  along  to  the  root  of  the  mastoid  process. 

At  the  third  vertebra  of  the  neck,  where  the  two  splenii  mus- 
cles part  from  each  other,  the  tendons  of  the  opposite  splenii 
are  closely  connected  both  with  each  other  and  with  the  com- 
mon tendon,  which  is  called  ligamentum  nuchas. 

This  is  the  splenius  capitis  ; but  there  is  a portion  of  this 
same  muscle  which  lies  under  this,  and  which  has  the  same 
common  origin,  but  which  terminates  by  four  or  five  distinct 
tendons  in  the  transverse  processes  of  the  upper  vertebras  of  the 
neck.  This  portion  may  be  dissected  apart,  and  has  been  con- 
sidered by  many  as  a muscle,  the  splenius  colli  of  Albinus ; 
who  has  distinguished  as  splenius  capitis  all  that  part  arising 
from  the  spines  of  the  neck,  and  implanted  into  the  head  ; and 
as  the  splenius  colli,  all  that  part  which  arises  from  the  verte- 
bral of  the  back,  and  is  implanted  into  the  transverse  proces- 
ses of  the  neck. 

These  splenii  are  the  right  antagonists  of  the  mastoid  mus- 
cles ; both  the  splenii  acting,  pull  the  head  directly  backward ; 
one  acting  turns  the  head  and  neck  obliquely  to  one  side ; one 
acting  along  with  the  corresponding  mastoid  muscle,  lays  the 
ear  down  upon  the  shoulder. 

CXIX.  The  complexes  is  named  from  the  intricacy  of  its 


HEAD  AND  NECK. 


209 


muscular  and  tendinous  parts,  which  are  mixed ; from  the 
irregularity  of  its  origins,  which  are  very  wide,  it  has  the  names 
of  coMPLExus  JMPLicATUs  TRIGEMINUS,  by  which  the  student 
is  warned  of  the^ifficulty  of  understanding  this  muscle. 

It  lies  immediately  under  thesplenius;  arises  by  distinct 
tendons,  with  ten  or  more  tendinous  feet  from  the  four  lower 
transverse  processes  of  the  veitebrae  of  the  neck,  and  from  the 
seven  uppermost  of  the  back ; having  also  some  less  regular 
origins  as  from  two  spines  of  the  back  and  from  four  oblique 
processes  in  the  neck.  It  grows  into  a large  muscle,  which  is 
not  like  the  splenius,  flat  and  regular,  but  thick,  fleshy,  com- 
posed of  tendon  and  flesh  mixed,  filling  up  the  hollow,  by  the 
sides  of  the  spines  of  the  neck,  and  terminating  in  a broad 
fleshy  head,  which  is  fixed  under  the  ridge  of  the  occipital 
bone  ; and  this  is  the  part  which  is  seen  in  the  angle  or  forking 
of  the  splenii. 

This  may  stand  as  the  general  description  of  the  muscle  con- 
sidered as  one.  But  Albinus  has  chosen  to  describe  it  as  two 
muscles,  under  two  different  names,  with  a minuteness  which, 
far  from  clearing  the  demonstration  of  any  difficulties,  makes 
it  less  distinct ; and  if  any  thing  could  complete  the  confusion, 
it  was  his  humour  of  calling  that  biventer,  which  had  been 
hitherto  named  complexes,  and  naming  the  lower  part  of  the 
muscle  complexes,  though  it  never  had  been  distinguished 
from  the  rest. 

The  BIVENTER  of  Albinus  is  the  upper  layer  of  the  muscle, 
that  part  which  appears  in  the  fork  of  the  splenii : and  if  we 
have  hitherto  named  it  complexus,  from  its  mixture  of  ten- 
dons and  flesh,  it  was  particularly  improper  to  transfer  that 
name  to  another  part  of  the  muscle  which  is  less  complicated. 
This  upper  layer,  the  biventer  cervicis,  is  attached  by  a 
large  broad  head  to  the  occipital  bone ; in  the  centre  of  this 
belly  there  is  a confusion  of  tendon ; then  there  is  a middle 
tendon  about  the  middle  of  the  arch  of  the  neck,  and  the  low- 
er part  of  the  biventer  arises  from  two  parts;  first  by  one  slip 
of  flesh  from  the  two  uppermost  spines  of  the  back;  and,  se- 
condly, by  a larger  fleshy  portion  which  comes  from  the  fourth, 
fifth,  sixth, and  seventh  transverse  processes  of  the  back.  And  it  is 
from  the  upper  and  lower  fleshy  heads  and  the  confused  mid- 
dle tendon  that  it  is  called  biventer. 

The  COMPLEXES  of  Albinus  lies  below  this  one.  It  arises 
by  three  tendinous  and  fleshy  slips,  from  the  three  upper  trans- 
verse processes  of  the  back.  Then  it  has  four  other  slips  from 
four  oblique  or  articulating  processes  of  the  neck;  which  va- 
rious origins  are  gathered  into  one  thick  irregular  fleshy  belly, 
which  is  implanted  into  the  occiput  under  the  great  head  of 
VOL.  1.  D d 


210 


MUSCLES  OF  THE 


the  biventer,  and  mixed  with  it.  This  I have  chosen  to  ex- 
plain, lest  the  student  should  be  embarrassed  by  false  names; 
referring  bim  to  the  first  paragraph  for  the  true  and  simple  des- 
cription of  this  muscle. 

CXX.  Trachelo-mastoideus.* — The  lafl  muscle  is  often 
named  complexus  major,  and  this  complexus  minor;  but 
a fitter  name  is  the  trachelo-mastoioeos,  from  its  origin 
in  the  neck,  and  its  insertion  in  the  mastoid  process. 

Its  origin  is  from  the  three  first  vertebras  of  the  back,  and 
from  the  five  lowest  of  the  neck  at  their  transverse  processes. 
Its  origins  are  by  distinct  tendons,  and  its  belly  is  in  some  de- 
gree mixed  of  tendon  and  flesh,  whence  its  name  of  com- 
plexus minor.  It  is  inserted  into  the  mastoid  process  just  under 
the  insertion  of  the  occipital  part  of  the  splenius ; and  indeed  its 
long  and  flat  belly  lies  all  along  under  that  muscle,  so  that  the 
order  of  dissection  is  this:  1.  The  trapezius.  2.  The 

SPLENIUS  CAPITIS.  3.  The  SPLENIUS  CERVicis.  4.  The 
TKACHELO-MASTOIDE  US.  f ? 

It  is  needless  to  speak  of  its  use,  since  the  use  of  all  these 
muscles  is  to  draw  the  head  backwards  directly,  when  both 
act ; obliquely,  when  one  acts  alone. 

The  RECTI  MUSCLES  are  two  deep-seated  muscles,  which  go 
immediately  from  the  vertebrze  to  the  occiput,  to  be  inserted 
into  its  lower  ridge.  They  are  called  major  and  minor, 

CXXI.  The  RECTUS  minor  is  the  shorter  of  the  two,  arising 
from  the  first  vertebra  of  the  neck.  Its  place  of  origin  is  a 
small  tuber  which  stands  in  the  place  of  the  spinous  process  of 
the  first  vertebra,  and  from  that  point,  where  it  is  tendinous, 
it  goes  up  to  the  occipital  ridge,  and  is  inserted  fleshy. 

CXXII.  The  RECTUS  major  is  larger.  It  arises,  in  like 
manner,  tendinous,  from  the  second  vertebra  of  the  neck  at 
its  spinous  process,  and  mounting  from  that,  is  inserted  fleshy 
into  the  lower  ridge  of  the  occiput  without  the  former.  These 
are  so  placed  that  the  recti  minores  appear  in  the  interstice  of 
the  recti  majores.  And  though  we  call  them  both  recti,  yet 
they  cannot  truly  be  so ; for  the  recti  minores  must  be,  in 
some  degree,  oblique,  and  the  recti  majores  still  more  so : 
and,  consequently,  although  their  chief  use  be  conjointly  to 
draw  the  head  directl)’^  backwards,  yet  one  acting  must  turn 
the  head  to  its  side.  And  indeed  the  same  may  be  said  of  all 
the  muscles  of  the  neck. 

The  OBLiQuus  SUPERIOR  and  OBLiquus  inferior,  cor- 
respond very  closely  in  all  things  with  the  recti ; but,  in  their 

* It  is  the  TRACHEI.O-MASTOIDEUS,  the  MASTOIDEUS  LATERALIS,  the  CAPITIS  PAR-TEBTipj., 

ihe  coMPLEECs^MiNOR  : by  some  it  is  considered  as  a part  pf  the  complexus. 


HEAD  AND  NECK. 


211 


oblique  direction  the  uppermost,  as  being  much  shorter,  has 
been  named  obliquus  minor,  the  lower  one  obliquus  major. 

CXXIII.  The  OBLIQUUS  supe“.ior  arises  from  the  trans- 
verse process  of  the  atlas,  and  is  inserted  into  the  end  of  the 
lower  occipital  ridge.  Its  use,  notwithstanding  its  oblique  po- 
sition, is  not  to  turn,  but  to  bend  the  head  backwards,  for  the 
occipital  condyles  standing  obliquely,  do  not  permit  the  rota- 
tory motion  of  the  head  on  the  first  vertebra.  Its  insertion  in- 
to the  occiput  is  under  the  splenius  and  complexus : but  one 
edge  of  it  is  above  the  insertion  of  the  rectus  major. 

CXXIV.  The  OBLIQUUS  inferior  rises  from  one  verte- 
bra and  goes  to  another.  It  arises  from  the  spine  of  the  se- 
cond vertebra  : it  goes  to  the  transverse  process  of  the  first, 
and  it  meets  the  superior  oblique  muscle  ; and  this  one  obtains 
great  power,  by  the  lateral  projection  of  the  atlas  giving  it  a 
lever  power.  The  first  vertebra  or  atlas  rolls  on  the  tooth-like 
process  of  the  dentatus;  and  while  the  great  and  slow  motions 
of  the  neck  in  general  are  performed  by  other  muscles,  there 
is  a presumption,  that  the  short  and  quick  turnings  of  the 
head  are  performed  by  these  oblique  muscles. 

MUSCLES  OF  THE  TRUNK. 

The  great  muscles  which  move  the  back  and  loins  are  the 

QUADRATDS  LUMBORUM,  8ACRO-LUMBALIS,  aild  LONGISSIMUS 
DORSl. 

The  sacro-lumbalis  and  longissimus  dorsi  run  by  the  side  of 
the  spine,  and  lie  immediately  under  the  latissimus  dorsi, 
which  is  the  outer  layer  ; the  quadratus  lumborum  lies  again 
under  these,  and  next  to  the  abdominal  cavity.  Although  the 
quadratus  lumborum  lies  deep  under  the  longissimus  dorsi  mus- 
de,  I shall  describe  it  first  for  the  sake  of  a connection  which 
will  be  presently  understood. 

CXXV.  The  QUADRATUS  LUMBORUM  is  a flat  squared  mus- 
cle named  quadratus  from  its  square,  or  rather  oblong  form. 
It  arises  fleshy  from  two  or  three  inches  of  the  back  part  of  the 
os  ilium,  and  from  the  ligaments  of  the  pelvis,  which  tie  the 
hack  part  of  the  ilium  to  the  side  of  the  sacrum,  and  to  the 
transverse  processes  of  the  loins.  As  it  goes  upwards  along 
the  side  of  the  lumbar  vertebrie,  it  takes  hold  of  the  points  of 
the  transverse  processes  of  each,  by  small  tendinous  slips ; so 
that  we  are  almost  at  a loss  whether  to  consider  these  as  new  ori- 
gins or  as  insertions  : butits  chief  insertion  is  into  the  lower  edge 
wfthe  last  rib,  and  a small  production  ef  it  slips  under  the  arch 


212 


BIUS€LES  OF  THE  TRUNK, 


of  the  diaphragm,  to  be  implanted  into  the  body  or  forepart; 
of  the  last  vertebra  of  the  back. 

The  LONGissiMUs  Doiibi  and  sacho-lumbalis  have  their 
origin  in  one  common  and  broad  tendon  coming  from  the  sa- 
crum, ilium,  and  loins  ; the  two  muscles  lie  alongside  of  each 
other;  the  longissimus  dorsi  is  nearer  the  spine,  and  keeps  its 
tendons  closer  by  the  spine.  The  sacro-lumbalis  is  farther 
from  the  spine,  and  spreads  its  tendinous  feet  broader  upon 
the  sides  of  the  thorax  : and  if  one  be  a little  under  the  other, 
it  is  the  outer  edge  of  the  longissimus  dorsi,  which  is  a little 
under  the  edge  of  the  lumbar  muscle. 

The  common  tendon  and  muscle  (for  there  is  for  some  way 
but  one  muscle)  begins  thus  : it  may  be  said  to  have  two  kinds 
of  adhesion  ; for,  first  externally  it  appears  a broad,  fiat,  and 
shining  tendon,  which  arises  tendinous  from  all  the  spines  of 
the  lumbar  vertebrae  ; from  the  spines  of  the  sacrum,  and  from 
the  back  part  of  the  os  ilium.  But  the  inner  surface  of  this 
broad  tendon  is  strongly  fleshy  ; for  it  arises  fleshy  from  the 
back  part  of  the  ilium  ; from  the  deep  hollow  betwixt  the 
ilium  and  sacrum  ; from  the  sides  of  the  long  spines  of  the  lum- 
bar vertebrae ; and  from  their  articulating  processes,  and  the 
roots  of  their  transverse  processes.  In  short,  its  origin  is  all 
tendinous  without,  and  all  fleshy  within ; and  its  flesh  arises 
from  all  that  irregular  surface  which  is  on  either  side  of  the 
spine  betwixt  the  os  ilium  and  the  vertebrae  of  the  loins  ; and 
thus  it  continues  one  strong  tendinous  and  fleshy  muscle,  fill- 
ing up  all  the  hollow  of  the  loins.  There  is  an  appearance  of 
separation,  something  like  a split  in  the  tendon,  which  shows 
in  the  loins  what  part  of  the  tendon  belongs  to  each  muscle  ; 
but  it  is  only  in  the  back  that  they  are  fairly  divided. 

Just  oppisite  to  the  lowest  rib,  the  longissimus  dorsi  and  sa- 
cro  lumbalis  break  off  from  the  common  tendon  ; and  the  lon- 
gissimus keeps  close  by  the  vertebra,  while  the  sacro  lumbalis 
is  implanted  into  the  ribs. 

CXXVI.  The  LONGISSIMUS  dorsi  is  a muscle  of  the  spine. 
It  is  not  a flat  muscle,  but  round,  thick,  and  firm,  filling  up  all 
the  hollow  betwixt  the  spine  and  the  angle  of  the  ribs.  It  is  of 
a long  form,  as  its  name  implies,  terminating  towards  its  top 
almost  in  a point.  It  has  two  distinct  sets  of  feet  by  which  it 
is  inserted  ; one  set  of  feet  more  fleshy,  but  small  and  neat,  go 
outwards  from  the  side,  as  it  were,  of  the  muscle,  to  be  im- 
planted near  the  heads  of  the  ribs  ; the  lower  ones  farther  out 
than  the  heads  of  the  ribs  ; the  upper  ones  close  to  the  head, 
and  consequently  closer  to  the  spine.  These  heads  are  nine 
or  ten  in  number,  corresponding  with  the  nine  orten  uppermost 
ribs.  Another  set  of  heads,  which  are  not  so  well  seen  as  this 


MUSCLES  OF  THE  TRUNK. 


2IS 


set,  because  they  lie  more  under  the  muscle,  are  small,  neat, 
and  tendinous ; they  go  in  an  opposite  direction,  \dz.  inwards 
and  upwards;  keep  closer  by  the  spine,  and  are  inserted  i o 
the  transverse  processes  of  the  vertebrae  of  the  back.  This  set 
of  heads  is  thirteen  in  number,  implanted  into  the  transverse 
processes  of  all  the  back,  and  of  one  vertebra  of  the  neck. 

CXXVn.  The  SACHo-LUMBAJUS  separates  from  the  longis- 
slmus  dorsi  at  thelat  rib,  and  is  a flatter  and  less  fleshy  muscle  : 
its  twelve  tendons  are  flatter  than  those  of  the  longissimus  dor- 
si,  and  go  out  wider  from  the  spine.  The  tendons  next  to  the 
longissimus  dorsi  run  highest  up,  and  are  the  longest  ; those 
farthest  from  the  spine,  (?.  e.)  farthest  out  upon  the  chest,  are 
the  shortest.  It  has  a flat  tendon  for  each  rib,  wljich  takes 
hold  upon  the  lower  edge  of  the  rib.  But  it  has  another  order 
of  small  muscles  which  mix  with  it ; for  as  the  longissimus 
dorsi  has  a double  row  of  insertion,  this  has  another  set  of 
attachment,  for  there  arises  from  the  surface  of  each  rib,  at 
least  of  the  six  or  seven  lowest  ribs,  a small  slip  of  flesh,  which 
runs  into  the  substance  of  the  sacro-Iumbalis,  and  mixes  with 
it ; and  these  fleshy  slips  go  by  the  name  of  the  auditamentum 

AD  SACRO-EUMBALEM  Or  MUSCULl  ACCESSORII. 

Both  these  muscles,  viz.  the  longissimus  and  sacro-lumbalis, 
terminate  in  points  which  reach  towards  the  neck,  and  under 
the  point  of  each  there  lie  the  roots  of  two  small  muscles,  which 
go  up  to  move  the  neck.  Many  have  referred  these  slips  go- 
ing up  into  the  neck  entirely  to  the  muscles  I am  now  descri- 
bing, calling  one  an  ascending  slip  of  the  longissimus  dorsi,  and 
the  other  a slip  of  the  sacro-lumbalis,  while  others  have  des- 
eribed  them  as  distinct  muscles,  having  but  slight  connections 
with  the  longissimus  and  sacro-lumbalis.  Their  proper  names 
are  cervicalis  descendens,  and  transversalis  colli. 

CXXVIII.  The  CERVICALIS  descendens  is  connected  with 
the  sacro-lumbalis  muscle ; it  cannot  be  entirely  referred  to  it, 
for  the  cervicalis  descendens  arises  as  a distinct  muscle  from 
the  five  lower  vertebrae  of  the  neck,  at  their  transverse  pro- 
cesses, goes  downwards  very  small  and  slender,  to  be  inserted 
into  the  six  uppermost  ribs,  to  get  at  which  it  slips  under  the 
longest  tendons  of  the  sacro-lumbalis  ; but  that  the  cervicalis 
descendens  does  not  belong  to  the  sacro-lumbalis  may  be  in- 
ferred from  its  having  distinct  tendons  from  six  ribs,  and  from 
five  transverse  processes  of  the  neck,  and  from  these  tendons 
being  in  a direction  which  does  not  at  all  correspond  with  the 
heads  of  the  sacro-lumbalis.  Indeed  the  longissimus  dorsi  has 
a better  claim  to  this  muscle  ; for  a long  slip,  partly  tendinous 
and  partly  fleshy,  runs  upwards  from  the  longest  tendon  of  the 
longissimus  dorsi,  to  join  itself  to  the  cervicalis  descendens,  ner  - 


214 


MUSCLES  OF  THE  TRUNK. 


haps  it  would  be  better  to  consider  it  a continuation  of  the  ac- 
cessorii  ad  sacr.  lumbal.* 

CXXIX.  The  TRANS  VERS  ALis  COLLI  is  that  which  Sabatier 
refers  to  the  longissimus  dorsi ; but  it  is  a distinct  muscle,  ari- 
sing partly  tendinous,  and  partly  fleshy,  from  the  five  upper 
transverse  processes  of  the  hack ; lies  betwixt  the  trarhelo- 
mastoideus  and  the  cervicalis  descendens;  goes  from  the 
transverse  processes  of  the  back  to  the  transverse  processes  of 
the  neck,  and  has  no  more  than  a confused  and  irregular  con- 
nection with  any  other  muscle. 

The  ^UADRATus  LUMBORUM  keeps  the  trunk  erect,  by  the 
action  of  both  muscles  at  once  ; inclines  it  to  one  side,  or  turns 
it  upon  its  axis,  when  one  only  acts ; and  by  its  insertion  into 
the  ribs,  must  assist  in  high  breathing,  by  pulling  down  the  ribs. 
The  LONGISSIMUS  DORSI  has  no  power  but  over  the  spine, 
which  it  bends  backwards,  acting  continually  in  keeping  the 
trunk  erect.  This  is  also  the  chief  use  of  the  sacro-lumbalis  j 
but  the  SACRO-LUMBALIS  going  out  further  upon  the  ribs,  takes 
such  hold  upon  them,  that  besides  its  common  action  of  raising 
the  trunk,  it  may,  on  occasions,  pull  them  down,  assisting  the 
quadratus  and  the  lower  serrated  muscle.  And  it  will  have 
greater  power  in  turning  the  trunk  of  the  body  upon  its  axis 
than  the  longissimus  dorsi,  which  pulls  almost  directly  back- 
wards. The  CERVICALIS  DESCENDENS  co-operates  with  the 
trachelo-mastoideus,  and  others,  which  turn  the  head  to  one 
side  ; and  the  cervicalis  descendens  bends  the  neck  to  one  side, 
both  the  one  and  the  other  being  independent  muscles. 

These  two  muscles  bring  us  to  mention  that  intricate  set  of 
muscles  which  fills  up  all  the  hollows  and  interstices  among  the 
spines  and  irregular  processes  of  the  vertebrae,  which  might  be 
fairly  reckoned  as  one  muscle,  since  they  are  one  in  place  and 
in  office,  but  which  the  anatomist  may  separate  into  an  infinite 
number,  with  various  and  perplexing  names  ; an  opportunity 
which  anatomists  have  been  careful  not  to  lose. 

The  surface  of  the  back,  from  the  bulge  of  the  ribs  on  one 
side,  to  the  bulge  of  the  ribs  on  the  opposite  side  of  the 
thorax,  is  one  confused  surface,  consisting  of  innumerable 
hollows,  processes,  and  points  of  bone  ; and  it  is  tied  from 
point  to  point  with  innumerable  small  muscles,  or  unequal 
bundles  of  mixed  tendon  and  flesh.  There  are  many  points, 

* Hence  it  is  plain  that  the  sacro-lumbalis  and  longissimus  dorsi  have  nearly  an  equal 
claim  to  this  cervicalis  descendens.  For,  first,  the  longissimus  dorsi  sends  its  longest  tendon 
fairly  up  into  the  cervicalis  de.scendens,  so  far,  tiiat  the  slip  is  implanted  into  the  transverse 
processes  of  the  neck.  And,  secondly,  tlie  feet  of  the  cervicalis  descendens  begin  under  tlie 
last  tendons  of  tlie  sacro-lumbalis,  so  as  to  have  tlie  appearance  of  arising  from  itssupplemen- 
tary  muscle,  tiie  additamentum,  and  being  a part  of  it ; and  indeed  Sabatier  has  described  it 
according  to  this  view. 


MUSCLES  OF  THE  TRUNK. 


215 


as  the  spinous,  transverse,  and  oblique  processes  of  the  ver- 
tebrce,  and  the  bulging  heads  and  angles  of  the  ribs ; and 
each  process,  or  at  least  each  set  of  processes,  has  its  distinct 
sets  of  muscles  and  tendons. 

1 . There  is  one  long  continuity  of  muscular  and  tendinous 
fibres  going  from  spine  to  spine,  and  lying  on  the  side  of  the 
spinous  processes  along  the  whole  length  of  the  back  and 
neck.  This  is  divided  into  the  spinalis  cervicis,  and  the 

SPINALIS  DO  RSI. 

2.  There  is  a similar  continuation  of  fibres,  with  less 
tendon  and  more  flesh,  belonging  one  half  to  the  spinous,  and 
the  other  half  to  the  transverse  processes,  whence  it  is  named 

SEMI-SPINALIS  DORSI. 

3.  There  is  a great  mass  lying  all  along  the  hollow  of  the 
back,  on  each  side  of  the  spinous  processes,  which  passing 
alternately  from  the  transverse  process  of  one  vertebra  to  the 
spinous  process  of  the  next  above,  is  of  course  split  into 
many  heads,  but  yet  having  such  connection  as  to  give  it  the 
form  and  name  of  a single  muscle,  the  mdltifidus  spin^;. 

4.  and  5.  There  are  yet  smaller  muscular  fasciculi  which 
stand  perpendicularly  betwixt  every  two  transverse  and  every 
iwo  spinous  processes;  thence  they  are  named  inter-trans- 
VERSARii  and  inter-spinales. 

CXXX.  The  spinalis  cervicis  is  that  which  is  im- 
planted into  the  spines  of  the  cervical  vertebrae ; but  because 
it  does  not  go  from  spine  to  spine,  like  the  spinalis  dorsi, 
but  from  transverse  processes  to  spines,  it  has  been  named  by 
Winslow,  SEMI-SPINALIS,  or  transverso-spinalis  colli. 
It  arises  from  the  transverse  processes  of  the  six  upper  verte- 
bra of  the  back,  and  is  inserted  into  all  the  spinous  process 
of  the  vertebriP  of  the  neck,  except  the  first  and  last ; and  it 
extends  the  neck,  or  by  its  obliquity  may  contribute  to  the 
turnings  of  the  neck,  or  to  bending  it  to  one  side.* 

C5Q5X1.  The  spinalis  dorsi  arises  from  two  spinous  pro- 
cesses of  the  loins,  and  from  the  three  lower  spines  of  the 
back,  and  passing  two  spines  untouched,  it  is  implanted  into 
all  the  spines  of  the  back,  except  the  uppermost.  This 
muscle  is  very  slender  and  long,  and  consists  fully  more  of 
tendon  than  of  flesh  : it  has  five  feet  below,  rising  from  the 
lower  spines  of  the  back  and  loins  ; and  nine  feet  above,  im- 
planted into  the  upper  spines  of  the  back.  Its  action  must 
raise  the  spine,  but  perhaps  it  may  be  equally  useful,  as  a 
muscular  and  tendinous  ligament. 

* The  TP.ANsvERSALis  cERvicts  (vide  p.  214.)  is  that  which  goes  from  the  transverse 
processes  of  the  back  to  the  transverse  processes  of  the  neck  ; while  this,  the  sn?j.\Tis- 
cERvins.  goes  from  the  transverse  processes  of  the  back  to  the  spines  of  the  neck. 


216 


MUSCLES  OP  THE  TRUNK. 


rXXXII.  The  SEM1-SP11VA.L1S  dorsi  arises  from  the  trans- 
verse processes  of  the  seventh,  eighth,  ninth,  and  tenth  ver- 
tebr®  of  the  back,  and  is  implanted  into  the  six  or  seven 
upper  dorsal  spinous  processes  and  into  the  two  last  of  the 
neck.* 

CXXXIII.  The  MULTiFiDus  spin®  runs  from  the  sacrum 
along  all  the  spine  to  the  vertebrae  of  the  neck;  and"  is  a compre- 
hensive and  true  way  of  describing  many  irregular  portions  of 
flesh,  which  authors  have  divided  into  distinct  muscles.f  It 
is  a continued  fleshy  indentation,  from  transverse  process  to 
spine,  through  all  the  vertebr®  of  the  back,  neck,  and 
loins. 

It  begins  both  tendinous  and  fleshy,  from  the  upper  convex 
surface  of  the  os  sacrum,  which  is  rough  with  spines,  from  the 
adjoining  part  of  the  illium  ; and  in  the  loins,  it  arises  from 
oblique  processes:  in  the  back,  from  transverse  processes; 
and  again  from  oblique  processes,  among  the  cervical  ver- 
tebrae. 

Its  origin  in  the  loins,  is  close  to  the  spine  ; being  from  the 
upper  oblique  processes,  and  from  the  root  of  the  transverse 
processes.  In  the  back  it  arises  from  the  transverse  processes, 
and  therefore  arises  there  by  more  distinct  heads.  In  the  |] 
neck  again,  it  arises  from  the  lower  oblique  processes,  more 
confusedly. 

Its  bundles  or  fasciculi  are  inserted  into  the  spinous  pro- 
cesses, sometimes  into  the  second,  or  even  into  the  third  or 
fourth  spine,  above  that  from  which  the  bundle  arises  ; for  the  m 
tendons  do  not  stop  at  that  spinious  process  which  they  first 
touch,  but  go  upwards,  taking  attachments  to  other  two  or 
three,  and  mixing  their  tendons  with  those  of  the  fasciculi, 
above  and  below  ; and  these  tendons  reach  from  the  first  of 
the  loins  to  all  the  vertebrae  up  to  the  atlas,  which  is  the  only 
one  not  included. 

The  use  of  the  multifidus  spinse,  is  to  retain  the  spine  from 
being  too  much  bent  forward ; for  these  muscles  serve  (as  I 
have  observed)  the  purpose  of  a ligament,  and  the  best  of 
all  ligaments,  having  a degree  of  strength,  exactly  pro- 
portioned to  the  necessity  for  strength.  It  also  moves  the 
spine  backwards,  though  perhaps  it  is  less  useful  in  this  than 
as  a ligament ; for  we  find  it  as  strong  in  the  vertebrae  of  the 
back,  which  have  little  motion  betwixt  the  individual  bones, 
and  what  little  there  is,  must  consequently  be  general.  It  ' 

* This  is  of  coui'se  the  transverso  spinalis  dorsi  of  Winslow.  | 

f TrANSVERSO-SPINALIS  LUMBOP.l'M,  SACER  ; SEMI-SPINAI.IS  INTERNUS,  Sive  TRANSVERSO- 
spiNALis  DOR.'i,  sEMi-spiNALis,  >ive  TRANSVERSO-spiNAi.is  COLLI,  pars  interna. — Winslow, 
Transvehsalis  lumborum,  vulgo  sace;r.  Thansversalis  dorsi.  Trajssversahs 
COIII. 


MUSCLES  OF  THE  TRUNK. 


217 


seems  rather  intended  to  moderate  the  lateral  motions  of  the 
vertebrae  than  to  produce  them  : when  it  acts,  its  chief  use  is 
either  to  resist  the  spine  being  bent  forward  by  a weight,  or  to 
erect  the  spine. 

CXXXIV.  The  inter-spinales  colli,  dorsi,  and  lum- 
BORUM,  have  varieties,  so  little  interesting,  that  they  need 
hardly  be  described.  The  inter-spinales  colli  are 
stronger,  because  the  neck  has  many  and  quick  motions,  and 
the  bifurcated  spines  of  the  neck  give  broader  surfaces  for 
these  muscles.  The  inter-spinales  dorsi  are  almost 
entirely  wanting,  because  the  spines  of  the  back  are  close 
upon  each  other,  and  the  vertebrae  are  almost  fixed.  The 
INTER-SPINALES  in  the  LOINS,  are  rather  tendons  or  liga- 
ments, than  proper  muscles. 

CXXXV.  The  iNTER-TiiANSTERSALES  are  again  stronger 
and  fuller  in  the  neck,  because  of  the  lateral  motions  of  the 
neck  being  free,  and  its  transverse  processes  forked.  They 
are  in  more  numerous  bundles,  where  the  motion  is  greatest, 
viz.  betivixt  the  atlas  and  dentatus ; and  it  is  there,  that 
Alhinus  coimts  his  inter-transversales  cervicis,  prio- 
RES-LATERALES,  &c.  The  inter-lransversarii  are  wanting  in 
the  BACK,  giving  place  to  the  hgaments,  by  which  they  are 
tied  to  each  other,  and  to  the  ribs;  but  in  the  loins,  the 
inter-transversarii  are  again  strong,  for  the  lateral  or  twisting 
motions  of  the  loins. 

The  muscles  on  the  forepart  of  the  head  and  neck  will 
complete  the  catalogue  of  those  belonging  to  the  spine,  and 
they  are  the  chief  antagonists  to  the  muscles  which  I have 
been  describing. 

CXXXVl.  The  PLATYSMA-MYOiDEs*  is  a very  thin  muscu- 
lar expansion,  like  the  cutaneous  muscle  in  animals.  It  is 
spread  over  the  other  muscles,  immediately  under  the  skin, 
and  covers  the  whole  neck  and  lower  part  of  the  face. 

It  arises  from  the  cellular  substance  and  aponeurosis,  which 
cover  the  pectoral  muscle,  the  deltoid  muscle,  and  the  clavi- 
cle. Its  origin  is  by  long  separate  fleshy  slips ; it  goes  like  a 
thin  integument  over  the  neck,  and  is  first  inserted  about  the 
depressor  anguli  oris,  and  then  going  over  the  masseter,  is  lost 
betwixt  the  muscles  and  the  integuments  of  the  cheek. 

Perhaps  it  serves  also  to  pull  down  the  skin  of  the  cheek, 
and  the  angle  of  the  mouth ; but  its  chief  insertion  is  into  the 
lower  jaw,  and  its  use  is  partly  to  pull  it  downwards,  but  prin- 
cipally to  act  as  a fascia,  binding  the  parts  in  the  neck,  and  in 


* The  PiATTSMA-MTOiDEs  IS  also  named  muscl  trs  cuta!5ei.'s  latissimus  coin, 

VOL.  I.  E e 


MUSCLES  OF  THE  TRUNK. 


21  a 

violent  respiration  to  press  down  the  blood  contained  in  the 
great  veins  of  the  neck. 

CXXXVII.  Mastoideus. — This  muscle  arises  partly  from 
the  clavicle,  partly  from  the  sternum.  Albinus  reckons  it  two 
muscles;  the  steuno-mastoideus,  and  cleido-mastoidkus  ; 
a more  common  name  is  the  steuno-cleido-mastoideus  ; but 
here,  as  in  other  things,  I adhere  to  what  is  plainest.  And 
the  most  familiar  and  easy  name  is  musculus  mastoideus,  | 
considering  the  clavicular  portion,  as  an  addition  only. 

Its  origin,  from  the  upper  part  of  the  sternum,  is  pretty  round. 

It  arises  again  flat  from  the  forepart  of  the  clavicle ; and  this 
second  origin  is  broad  and  fleshy,  while  the  first  one  is  tendi- 
nous and  pointed.  These  two  heads  form  together  a very 
big  strong- bellied  fleshy  muscle,  which  is  inserted  into  the 
mastoid  process  by  a broad  tendon,  which  indeed  surrounds 
the  mastoid  process,  and  from  that  extends  still  backwards, 
towards  the  lambdoidal  suture.  When  one  of  the  mastoid 
muscles  acts,  it  turns  the  head  to  one  side;  when  both  act^ 
they  pull  the  head  directly  forwards. 

CXXXVTII.  Rectus  inteknus  capitis  major. — There 
are  three  muscles  on  each  side,  lying  under  the  oesophagus, 
trachea,  and  great  vessels,  flat  upon  the  forepart  of  the  verte- 
brae ; and  this  is  the  first  and  longest. 

Although  this  be  called  rectus,  it  is  oblique,  and  runs  ra- 
ther on  one  side ; for  it  arises  from  the  transverse  processes  of 
the  five  lower  vertebrae  of  the  neck,  and  it  is  inserted  into  the 
cuneiform  process  of  the  occipital  bone,  just  before  the  fora- 
men magnum. 

CXXXIX.  Rectus  internus  minor. — This  is  an  exceed- 
ingly small  muscle.  It  lies  immediately  under  the  rectus 
MAJOR  : it  arises  from  the  forepart  of  the  body  of  the  first  ver- 
tebrae, the  atlas,  and  going  (like  the  other  rectus)  obliquely  in- 
Avards,  it  is  inserted  into  the  occipital  bone,  near  the  condyle. 

CXL.  And  the  rectus  capitis  lateralis  is  another  small 
piuscle  like  the  former,  which  arises  from  the  transverse  pro- 
cesses of  the  first  vertebra,  and  is  inserted  into  the  side  of  the 
cuneiform  process  of  the  occipital  bone.  It  lies  immediately 
under  the  exit  of  the  great  jugular  vein. 

CXLI.  Lonrus  colli. — This  is  the  chief  of  those  muscles 
which  lie  upon  the  forepart  of  the  neck ; it  is  very  long,  arising 
from  the  flat  internal  surface  of  the  vertebrae  of  the  back,  to 
go  up  along  those  of  the  neck. 

Its  origin  is  first  within  the  thorax,  from  the  three  upper- 
most vertebrai  of  the  back,  from  the  flat  part  of  their  bodies, 
and  then  from  all  the  transverse  processes  and  bodies  of  the 
neck,  except  the  three  upper  ones.  It  is  inserted  tenUinoift 


MUSCLES  OP  THE  TRUNK.  219 

into  the  forepart  of  the  second  vertebra;  of  the  neck,  where 
the  opposite  large  muscles  meet  in  one  point  almost* 

x\Il  these  muscles,  which  lie  thus  flat  upon  the  plain  surface 
of  the  vertebrte  of  the  neck,  pull  the  head  and  neck  directly 
forwards ; or  when  one  acts,  they  are  of  use  in  pulling  it  to- 
wards one  side ; though  I rather  suppose  this  motion  is  perform- 
ed by  the  external  muscles  chiefly. 

CXLIl.  The  SCALENUS  I consider  as  one  muscle  ; for  it  is 
one  in  origin,  insertion,  and  office.  Its  origin  is  from  the 
rvhole  upper  surface  of  the  first  rib,  from  its  cartilage  backwards, 
and  also  from  the  second  rib ; and  its  insertion  is  into  the 
transverse  processes  of  the  vertebrae  of  the  neck.  But  by  its 
broad  origin,  and  its  very  long  insertion,  it  gives  opportunity 
for  dividing  it  into  several  fasciculi ; and  accordingly  it  has 
been  so  divided;  but  these  divivions  are  entirely  modern,  ar- 
tificial, and  unnatural.  The  ancients  considered  it  as  one 
triangular  muscle.  Winslow  divided  it  into  two,  the  primus 
and  secundus ; Cowper  into  three;  Douglas  into  four;  and 
Albinus  divides  it  into  five  muscles.  The  ancients  called  it 
scalenus,  from  its  resemblance  to  the  scalen  triangle ; and  the 
true  anatomy  is,  to  consider  it  as  one  great  triangular  muscle, 
flat,  and  stretching  from  the  ribs  to  the  neck,  closing  the  tho- 
rax above,  and  giving  passage  to  the  nerves  and  vessels  of  the 
arm. 

If  it  were  to  be  described  in  distinct  portions,  it  would  be  in 
in  three  parts.  The  anterior  portion  arises  from  the  trans- 
verse processes  of  the  fourth,  fifth,  and  sixth  vertebrae  of  the 
neck,  and  is  inserted  into  the  flat  part  of  the  first  rib  hard  by 
its  cartilage.  The  middle  portion  from  the  transverse  pro- 
cesses of  all  the  vertebrae  of  the  neck  goes  to  the  outer  edge  of 
the  rib,  and  extends  along  all  its  length.  The  posterior  portion 
arises  from  the  transverse  processes  of  the  fourth,  fifth,  and 
sixth  vertebras.  It  is  inserted  into  the  upper  edge  of  the 
second  rib,  about  an  inch  or  more  from  its  articulation  with 
the  spine. 

The  first  head  is  tendinous  and  fleshy  at  its  insertion  into 
the  rib;  but  the  second  and  third  heads  are  tendinous,  both 
in  their  origins  and  insertions. 

The  nerves  pass  in  the  interstice  betwixt  the  first  and  se- 
cond portions. 

The  oflBce  of  the  scalenus  muscle  is  to  pull  the  neck  to  one 
side,  or  to  bend  the  head  and  neck  forward,  when  both  act ; 
and  when  the  neck  is  fixed  backwai’ds,  they  may  perhaps  raise 
the  ribs ; for  asthmatics  are  observed  to  throw  the  head  back- 
wards,  in  order  to  raise  the  chest  with  greater  power. 

* The  longas  coUi  raascle  h in  part  covered  by  the  recto? 


220 


MOSCLES  of  the  ABDOMEKj 


CHAP.  VI. 

OF  THE  MUSCLES  OF  THE  ABDOMEN.  AND  OF 
THE  DIAPHRAGM. 

The  abdominal  muscles  cover  in  the  belly,  contain  the 
bowels,  and  take  a firm  hold  upon  the  pelvis  and  the  trunk. 
The  diaphragm,  again,  is  a moving  partition  betwixt  the  tho- 
rax and  the  abdomen  ; and  the  diaphragm,  pressing  down  the 
bowels  upon  the  abdominal  muscles,  enlarges  the  thorax  ; and 
the  abdominal  muscles  re-acting,  push  the  bowels  bark  upon 
the  diaphragm,  and  compress  the  thorax.  Thus,  the  alternate 
yielding  and  re-action  of  the  abdominal  muscles  and  diaphragm 
perform  breathing,  agitate  the  bowels,  promote  the  circulation, 
expel  the  fceces  and  urine,  assist  the  womb  in  the  delivery  of 
the  child.  And,  with  all  these  important  uses,  the  abdominal 
muscles  bend  and  turn  the  trunk,  and  fix  it  for  the  stronger  ac- 
tions of  the  limbs.  They  steady  the  body  in  lifting  weights, 
in  bearing  loads,  in  all  our  more  violent  exertions  they  often 
give  way  under  this  double  office  of  breathing,  and  of  strain- 
ing, along  with  the  rest  of  the  body;  and  the  bowels  coming 
out  through  their  natural  openings,  or  by  bursting  through  the 
interstices  of  their  fibres,  form  hernias  of  various  kinds. 
Whence  the  anatomy  of  these  muscles  is  most  interesting  to 
the  surgeon. 

The  muscles  of  the  abdomen  are  five  on  each  side.  1.  The 
outer  oblique  muscle,  to  which  the  names  of  nnscEMiENS, 
DECLivis,  and  ma.tor,  are  added,  because  it  is  the  outermost  of 
all  the  abdominal  muscles;  because  it  is  the  largest,  covering 
all  the  side  of  the  abdomen  with  its  fleshy  belly,  and  all  the 
forepart  of  the  abdomen  with  its  broad  expanded  tendon ; 
and  it  is  called  declivis,  or  descendens,  because  its  fleshy 
belly  begins  above,  upon  the  borders  of  the  thorax ; and  be- 
cause both  its  muscular  and  tendinous  fibres,  w'hicb  lie  paral- 
lel to  each  other,  run  obliquely  from  above  downwards  and 
inwards. 

2.  The  OBLiquus  internus  is  named  from  its  being  within 
the  first,  and  has  the  names  of  ascend ens  vel  minor  super- 
added,  because  its  fleshy  belly  is  smaller  than  that  of  the 
first,  arises  below,  chiefly  in  the  hailnch-bone,  and  all  its  fibi’es 
go  from  below  upwards. 

3.  The  TRANSVEUSALis  lies  under  all  the  others,  and  next 
to  the  cavity  of  the  abdomen,  and  has  but  one  name  which, 


AND  OF  THE  DIAPHRAGM.  221 

also  is  derived  from  the  direction  of  its  fibres  running  across, 
or  round  the  abdomen. 

4.  The  RECTUS,  so  named,  because  of  its  running  on  the 
forepart  of  the  abdomen,  in  one  straight  line  from  the  os 
pubis  to  the  sternum. 

6.  The  pvKAMiDAL  muscle  is  the  only  one  named  from  its 
shape.  It  is  a small,  neat,  conical  muscle,  which  arises  from 
the  os  pubis,  by  a broad  basis,  and  has  its  apex  turned  up- 
wards ; but  it  is  not  always  found,  for  it  is  only  as  a supplement 
to  the  recti  muscles,  and  as  a part  of  them,  whence  it  has 
been  named  musculus  succenturiatus,  or  supplementary 
muscle. 

CXLIII.  The  EXTERNAL  OBLiQ,UE  musclc  arises  from  the 
ribs,  and,  like  all  the  others  which  arise  from  ribs,  is  a ser- 
rated muscle.  It  comes  from  the  eight  lower  ribs,  by  distinct 
fleshy  tongues,  one  from  each  rib.  These  serrae  are  mixed 
with  the  indentations  of  the  serratus  major  anticus  muscle, 
which  goes  off  in  an  opposite  direction,  and  with  the  origin 
of  the  pectoralis  major  and  latissimus  dorsi.  The  origin  of 
the  muscle  lying  broad  upon  the  border  of  the  chest,  it  is  its 
thickest  and  most  fleshy  part,  whence  its  fibres  go  down  all 
in  one  direction,  parallel  with  each  other,  but  oblique  with 
respect  to  the  abdomen.  Its  fleshy  belly  ceases  about  the 
middle  of  the  side.  Its  flat  sheet  of  tendon  goes  over  the 
forepart  of  the  belly,  till  it  meets  its  fellow  exactly  in  the 
middle,  so  that  one  half,  or  the  back  part  of  the  abdomen, 
is  covered  by  its  fleshy  belly,  and  the  forepart  by  its  tendi- 
nous expansion. 

The  muscle  meets  its  fellow  in  the  middle  of  the  belly  j 
and  this  meeting  forms  (along  with  the  other  tendons)  a white 
line  from  the  pubes  to  the  sternum,  which  is  named  linea 
ALBA.  It  also,  before  it  reaches  the  middle,  adheres  to  the 
flat  tendon  of  the  Internal  oblique.  This  meeting  is  about 
four  inches  on  either  side  of  the  linea  alba,  and  is  a little  in- 
clined to  the  circular,  whence  it  is  named  linea  semilunaris. 
And,  finally,  this  muscle  is  implanted  into  the  spine  of  the 
ilium,  fleshy  about  the  middle  of  the  ilium,  tendinous  at  the 
forepart,  or  spinous  process  of  the  ilium,  and  still  tendinous 
into  the  whole  length  of  that  ligament,  which  extends  from 
the  spine  of  the  ilium  to  the  crest  of  the  pubes. 

This  is  the  whole  of  its  insertion,  viz.  all  the  length  of  the 
linea  alba,  fronj  the  pubes  to  the  sternum,  the  forepart  of 
the  spine  of  the  ilium,  and  the  ligament  of  Paupart,  which, 
though  it  is  commonly  thought  to  be  but  the  tendon  of  the 
external  oblique  reaching  from  point  to  point,  is,  in  truth,  a 


222  MUSCLES  OF  THE  ABDOMEN, 

distinct  ligament,  independent  of  the  tendon,  and  stronger 
than  it. 

CXLIV.  Obliquus  internus  abdominis. — The  chief  part 
of  this  muscle  arises  thick  and  fleshly  from  all  the  circle  of 
the  spine  of  the  ilium,  with  its  fibres  directed  upwards.  But, 
to  be  accurate,  we  must  describe  it  as  arising  from  the  whole 
length  of  the  spine  of  the  ilium,  from  the  joining  of  the  ilium 
and  sacrum,  from  the  spines  of  the  sacrum  itself,  and  from 
the  three  lower  spinous  processes  of  the  loins  ;*  and,  lastly, 
it  arises  from  nearly  half  of  the  ligament  of  the  thigh,  at  its 
end  next  to  the  ilium  ; but  still  the  chief  belly  is  at  the  iliac 
spine.  From  that  it  spreads  upwards  in  a radiated  form  ; the 
central  fibres  only  are  direct,  going  across  the  abdomen  to  the 
linea  alba ; the  higher  fibres  ascend  and  go  towards  the 
sternum,  and  the  lower  ones  go  obliquely  downwards  to  the 
pubes.  Its  flat  tendon  is  like  that  of  the  external  oblique, 
and  it  is  inserted  into  the  cartilages  of  the  seventh,  and  all 
the  false  ribs,  into  the  ensiform  cartilage  of  the  sternum,  and 
into  the  linea  alba,  through  its  whole  length,  and  the  os 
pubis. 

CXLV.  The  transversalis  abdominis  forms  the  internal 
layer,  it  runs  directly  across  the  belly.  It  arises  fleshy  from 
the  inner  surface  of  the  seven  lower  ribs,  where  its  digitations 
mix  with  those  by  which  the  diaphragm  arises;  tendinous 
from  the  transverse  processes  of  the  four  lower  lumbar  verte-  || 
br^,  and  last  of  the  back ; from  the  whole  spine  of  the  os 
ilium  internally,  and  from  a part  of  the  femoral  ligament. 
Upon  the  whole,  its  origin  is  like  that  of  the  inner  oblique 
, muscle ; its  fibres  go  across  the  abdomen,  and  its  tendon  is 
inserted  into  the  whole  length  of  the  linea  alba,  cartilage 
ensiformis  and  os  pubis. 

The  succession  in  which  these  three  muscles  arise  from  the 
chest,  is  this  : the  external  oblique  muscle  lies  broad  upon 
the  outside  of  the  chest,  and  so  its  tongues  mix  with  the 
tongues  of  the  serratus  anticus  major.  The  internal  oblique 
muscle  again  rises  lower  down  the  thorax,  frorn  its  edge, 
from  the  cartilages  of  the  ribs.  The  transverse  muscle  arises 
within  the  thorax,  from  the  internal  surface  of  the  ribs,  oppo- 
site to  where  the  tongues  of  the  external  oblique  lie  ; and  the 
diaphragm  arising  from  the  same  ribs,  mixes  its  indigitations 
with  the  transversalis,  so  that  Gaspar  Bartholin,  observing 
this  indigitation  to  be  very  curious  in  the  larger  animals,  be- 
lieved the  diaphragm  and  transverse  muscles  to  be  but  one 
great  trigastric,  or  three-bellied  muscle,  surrounding  all  the 

* This  origin  from  the  spinous  processes  of  the  loins,  is  a thin  tendon,  common  with  Ihs 
serratus  and  latisshnus  dorsi  muscles. 


and  of  the  diaphragm. 


223 


abdomen.  But  the  transversalis,  with  the  other  abdominal 
muscles,  are  the  antagonists  of  the  diaphragm. 

CXLVI.  The  KKCTi  muscles  cover  the  abdomen  on  its 
forepart,  in  a line  from  the  pubes  to  the  sternum,  and  they 
belong  so  equally  to  the  sternum  and  to  the  os  pubis,  that  it 
is  indifferent  which  we  call  their  origin,  and  which  their 
insertion.  The  origin  (as  I should  call  it)  of  each  rectus 
muscle  is  in  the  sternum,  is  broad  and  fleshy,  lies  upon  the 
outside  of  the  sternum,  covering  part  of  it,  and  all  the 
xiphoid  cartilage,  and  touching  and  mixing  its  fibres  with  the 
great  pectoral  muscle,  and  likewise  taking  part  of  its  origin 
from  the  cartilages  of  three  of  the  ribs.  It  is  about  four 
inches  broad  all  down  die  abdomen,  and  terminates  at  the 
side  of  the  symphysis  pubis,  with  a flat  and  pointed  tendon 
about  an  inch  in  length,  and  about  an  inch  broad.  This 
muscle  is  crossed  at  intervals  by  four  tendinous  intersections, 
which  divide  it  into  five  distinct  bellies.  Commonly  there 
are  three  bellies  above  the  umbilicus,  and  two  below ; but 
the  recti  muscles  are  the  least  regular  of  all  the  muscles  of 
the  abdomen.  Vesalius,  Albinus,  and  Sabatier,  were  thought 
to  have  found  the  recti  abdominis  extending  up  to  the  throat. 
But  it  is  now  found  that  Vesalius  had  only  represented  the 
muscles  of  a monkey,  or  of  a dog,  which  - are  very  long, 
upon  the  thorax  of  a human  subject.  Sabatier,  upon  revising 
his  notes,  retracts  what  he  had  said  : and  Albinus  also  is  sup- 
posed to  have  seen  only  a production  of  the  mastoid  muscle, 
extending  down  the  breast ; for  irregularities  of  this  kind  have 
been  found. 

CXLVII.  The  pyramidal  muscles  are  as  a supplement  to 
the  recti.  There  is  a small  neat  pyramidal  muscle  on  each 
side,  or  rather  a triangular  muscle,  fleshy  through  its  whole  ex- 
tent and  length,  with  its  base  turned  towards  the  pubes,  and 
its  apex  towards  the  umbilicus ; so  that  its  origin  is  in  the  crest 
of  the  pubes,  and  its  pointed  insertion  in  the  linea  alba  : and 
though  the  recti  muscles  have  been  supposed  byMassa  to  re- 
late to  the  penis,  or  by  Fallopius  to  belong  to  the  urinary  blad- 
der, their  true  use  is  only  to  assist  the  rectus  to  draw  down  the 
sternum,  and  tighten  the  linea  alba,  and  so  to  give  greater 
power  to  the  oblique  and  transverse  muscles.  The  pyramidalis 
is  so  irregular  a muscle,  that  sometimes  two  are  found  on  one 
side,  and  none  at  all  on  the  other.  Sometimes  two  on  each 
other;  sometimes  there  is  but  one,  and  very  often  they  are 
wanting,  the  belly  of  the  rectus  coming  quite  dowm  to  the 
pubes. 

1.  The  LINEA  ALBA  is  the  common  meeting  of  all  the  thin 
flat  tendons,  and  therefore  w'e  call  it  their  insertion,  being  the 


224  MUSCLES  OF  THE  ABDOMEN, 

common  point  towards  which  they  all  act;  it  is  white,  by  the 
gathering  of  all  the  colourless  tendons. 

2.  The  LiNEA  SEMILUNARIS  is  a line  of  the  same  white  ap- 
pearance, of  a circular  form,  and  produced  by  the  meeting  of 
all  the  tendons,  on  the  edge  of  the  rectus  muscle,  to  form  a 
sheath  for  it. 

3.  The  SHEATH  for  the  rectus  muscle  does  not  admit  of 
so  brief  a definition  as  this:  it  has  been  commonly  supposed 
to  be  formed  in  a very  curious  manner,  chiefly  by  the  broad 
tendon  of  the  obliquus  internus,  which  being  the  central  mus- 
cle, betwixt  tbe  two  other  layers,  is  supposed  to  have  its  ten- 
don split  into  two  thin  sheets ; that  the  outermost  sheet  ad- 
heres to  the  outer  oblique  muscle,  forming  tbe  outer  part  of 
the  sheath,  while  its  inner  sheet  adheres  to  the  tendon  of  the 
transverse  muscle,  forming  the  inner  part  of  the  sheath  ; but 
this  is  loo  intricate,  and  can  hardly  be  proved  by  dissection. 
Cowper  expresses  his  doubts  about  this  doctrine  of  the  tendon 
of  tbe  inner  oblique  muscle  being  split  into  two  layers ; and  I 
think  the  truest  description  is  this,  that  all  the  tendons  meet 
and  adhere  in  the  semilunar  line  ; that  they  immediately  part 
to  form  this  sheath  ; that  the  flat  tendons  of  both  the  oblique 
muscles  go  upon  tbe  outer  surface  of  the  rectus,  to  form  that 
side  of  the  sheath ; that  the  tendon  of  the  transverse  muscle 
only  lies  under  the  rectus,  forming  the  lower  part  of  the  sheath, 
and  that  it  is  unassisted  by  any  lamella  of  the  inner  oblique 
muscle  ; that  the  sheath  is  complete  at  the  forepart,  or  over 
the  muscle  ; but  that  under  the  muscle  the  sheath  stops  about 
five  or  six  inches  above  the  pubes,  and  that  there  the  recti  mus- 
cles (or  in  their  place  the  pyramidal  muscles)  lie  bare  upon  the 
bladder,  and  other  abdominal  viscera,  lined  only  by  the  thin 
peritonaeum.*  And  that  this  back  layer  of  the  sheath  is  thin- 
ner and  more  delicate,  and  but  little  attached  to  the  back  part 
of  tbe  rectus  muscle,  which  is  easily  raised  in  dissection,  while 
the  forepart  of  the  sheath  adheres  firmly  to  the  forepart  of  the 
muscle,  forming  those  cross  bands,  or  tendinous  intersections 
which  divide  the  rectus  into  bellies,  and  the  sheath  where  it 
lies  over  the  muscle  cannot  be  dissected  without  a degree  of 
violence,  either  to  the  sheath,  or  to  these  tendinous  intersec- 
tions. 

4.  The  UMBILICUS  is  that  opening  in  the  centre  of  the  abdo- 
men, in  the  middle  of  the  linea  alba,  through  which  the  nutri- 
tious vessels  of  the  foetus  pass.  The  vessels  have  degenerated 

* Cowper  had  never  observed  this  but  once,  that  the  lower  part  of  the  rectus  was  not 
lined  by  the  tendon  of  the  transversalis.  He  concluded,  that  in  this  instance  it  was  a sport 
ing  of  nature:  “so  much  a liisns  naturse,  that  accidents  like  this  might  he  the  cause  ofcer 
tain  rupture".*' 


AND  OF  THE  DIAPHRAGM. 


225 


Tato  ligaments  in  the  adult,  and  the  umbilicus  is  closed  in  the 
form  of  a ring;  but  sometimes  it  is  forced  by  violent  action, 
and  the  viscera  come  out  by  it,  forming  umbilical  hernia. 

5.  The  RING  of  the  abuominal  muscles  isthat  opening  near 
the  lower  part  of  the  abdomen,  just  over  the  pubes,  through 
which  the  spermatic  cord  passes  in  men,  and  the  round  liga- 
ment of  the  womb  in  women. 

Cowper  (p.  5.)  says  that  the  spermatic  cord  passes  through 
separate  rings,  in  each  of  the  three  abdominal  muscles ; and, 
like  older  authors,  he  makes  nature  exceedingly  wise,  in  pla- 
cing the  rings  not  opposite  to  each  other,  but  one  high,  and 
another  lower,  and  a third  lower  still,  so  as  to  prevent  the 
bowels  falling  out.  But  the  truth  is,  that  neither  the  internal 
oblique  nor  the  transverse  muscles  have  any  share  at  all  in  the 
ring,  which  belongs  entirely  to  the  external  oblique  muscle, 
and  is  formed  in  this  way  : all  the  tendinous  fibres  of  the  exter- 
nal oblique  are,  like  the  muscle  itself,  oblique,  running  from 
above  downwards ; and  the  tendinous  fasciculi  are  in  some 
places  wider,  a little  disjoined  from  each  other,  and  resembling 
stripes,  crossed  by  small  threads  of  tendon,  as  if  the  long  fibres 
were  in  danger  of  parting  from  each  other,  so  as  to  leave  a 
gap,  and  were  held  together  by  these  cross  threads ; and  it  is 
in  fact  a wider  and  perfect  separation  of  two  fibres  that  forms 
the  ring,  and  a stronger  interlacement  of  cross  fibres,  that  se- 
cures it  from  splitting  farther  up.  But  the  chief  security  of  the 
ring  is  by  the  form  of  the  opening ; for  it  is  not  a ring,  as  we 
call  it,  but  a mere  split  in  the  tendon,  which  begins  about  an 
inch  and  a half  above  the  pubes,  is  oblique,  and  looking  to- 
wards the  pubes,  like  the  fibres  which  form  it,  and  consists  of 
two  legs,  or  pillars  of  the  ring,  as  they  are  called ; for  the  up- 
per slip  which  forms  the  upper  part  of  the  opening,  goes  direct- 
ly towards  the  crest,  or  highest  point  of  the  pubes ; the  lower 
pillar,  or  the  slip  which-  forms  the  lower  line  of  the  slit,  turns  in 
behind,  gets  under  the  upper  one,  and  is  implanted  into  the 
pubes,  within  and  behind  the  upper  pillar:  this  lower  slip 
forms  at  once  the  lower  pillar  of  the  ring  and  the  edge  of  the 
femoral  ligament. 

Now  this  crossing  of  the  pillars  of  the  ring  secures  it ; for  the 
more  the  muscle  pulls,  in  pressing  upon  the  abdominal  viscera, 
the  tighter  is  the  slit  drawn  ; and  the  obliquity  of  the  opening 
gives  the  direction  to  hernise  of  the  groin,  which  always  point 
towards  the  pubes,  so  as  to  fall  into  the  scrotum  in  men,  or  in- 
to the  labia  pudendi  in  women,  keeping  close  by  the  groin. 

The  spermatic  cord,  formed  of  the  vessels  belonging  to  the 
testicle,  passes  through  this  ring  of  the  external  oblique  mus- 
cle; but  as  the  internal  and  oblique  transverse  muscles  form  no 

VOL.  I.  F f 


'226 


MUSCLES  OF  THE  ABDOMEN, 


share  in  the  ring,  the  cord  passes  by  their  lower  edge,  but  noi 
through  them.  At  the  place  where  the  cord  passes  obliquely 
under  the  edge  of  the  internal  oblique  muscle,  it  sends  a bun- 
dle of  fleshy  fibres  down  along  the  cord,  which  go  all  along  the 
cord,  gradually  extend  towards  tl>e  testicle,  expanding  and 
growing  thin  upon  the  upper  end  of  the  testicle,  and  gradually 
disappearing  on  the  tunica  vaginalis. 

CXLVIIl.  The  CKEMASTEii  MUSCLE  of  the  TESTICLE,  which 
is  a thin  slip  of  fibres  from  the  internal  oblique  muscle  of  the 
abdomen,  which  is  designed  for  suspending  the  testicle,  and 
for  drawing  it  up,  is  very  thick  and  strong  in  the  lower  animals, 
as  in  bulls,  dogs,  &c. ; is  easily  found  in  man,  but  not  always, 
being  sometimes  thin  and  pale,  and  hardly  to  be  known  from 
the  coats  upon  which  it  lies.  It  appears  to  grow  more  fleshy 
in  old  age  and  to  be  thickened  in  enlargements  of  the  testicle, 
the  better  to  support  the  weight. 

6.  The  LIGAMENT  of  the  thigh*  is  a distinct  ligament,  and 
not  merely  the  tendon  of  the  external  oblique,  rounded  and 
turned  in.  It  arises  from  the  spinous  process  of  the  ilium,  and 
is  inserted  into  the  crest  of  the  pubis.  It  receives  the  external 
oblique  muscle,  for  the  tendon  is  implanted  into  it.  Part  of 
the  flesh  of  the  internal  oblique  muscles  arise  from  the  outer 
end  of  the  ligament.  It  forms  an  arch  over  the  psoas  and 
iliacus  internus  muscles,  where  the  great  artery  of  the  thigh, 
and  its  anterior  nerve  pass  out,  and  it  is  tied  down  at  both  sides  || 
of  the  passage  for  the  vessels  by  the  fascia  of  the  thigh.  The 
great  vein  and  the  lymphatics  of  the  limb,  return  under  it  to  get 
into  the  abdomen  ; the  lymphatic  glands  of  the  groin  lie  here  ; 
the  whole  interstice  is  surrounded  and  filled  up  by  cellular  sub- 
stance and  fat,  but  it  is  not  firm  ; the  playing  of  the  muscles 
and  the  fat,  and  inguinal  glands,  keep  it  open  and  lax ; and  the 
bowels  are  apt  to  fall  down  here,  especially  in  women,  where 
the  point  of  the  ilium  is  high,  and  the  arch  wide. 

It  often  happens,  that  in  vomiting,  in  violent  coughing,  in 
straining  at  stool,  or  in  lifting  heavy  weights,  the  natural  ope- 
nings are  forced,  and  the  bowels  descend.  The  umbilicus  is 
very  seldom  forced  by  sudden  exertion,  for  it  is  a very  firm  i 
ring;  but  it  is  slowly  dilated  in  pregnancy,  and  hernia  of  the 
navel  is  infinitely  more  frequent  with  women  than  with  men. 
The  opening  of  the  king  is  often  kept  dilated  by  the  bowels 
following  the  testicle  when  it  descends  ; forming  the  congenital 
hernia ; most  frequently  of  ail,  the  ring  is  forced  in  strong 
young  men  by  hard  and  continued  labour  or  by  sudden  strain- 

This  ligament  of  the  thigh  is  named  also  the  inguinal  ligamhnt  ; the  guubal  arch  : 
tlie  LIGAMENT  of  PaUPART  ; the  LIGAMENT  of  FaLI.OMUS,  &C. 


AND  OF  THE  DIAPHRARM. 


227 


»ng;  but  women  are  safer  from  this  kind  of  hernia,  because 
the  round  ligament  of  the  womb  is  smaller  than  the  spermatic 
cord,  and  the  ring  in  them  is  very  close. — Abdominal  HERNia; 
are  those  which  come  not  through  any  natural  opening,  but 
through  the  interstices  of  the  muscles,  or  their  tendons;  some- 
times hernia  follows  a wound 4jf  the  abdomen  ; for  a w'ound 
of  the  abdominal  muscles  may  not  heal  so  neatly  as  not  to 
leave  some  small  interstice,  through  which  the  bowels  pro- 
trude. Thus  any  point  may  be  forced  by  violence  ; any  of 
the  openings,  or  all  of  them,  may  be  relaxed  by  weakness,  as 
in  dropsical  or  other  lingering  diseases  : for  it  is  from  this  cause 
that  heruiae  are  more  frequent  in  childhood  and  in  old  age,  by 
the  laxity  which  is  natural  to  childhood,  or  by  the  weakness 
natural  to  the  decline  of  life.  Often  there  seems  to  be  a 
hereditary  disposition  to  hernias  in  certain  houses,  the  form  of 
the  openings  of  the  abdomen  being  wider  in  a whole  family, 
just  as  the  features  of  the  face  are  peculiar.  And  I have  seen  a 
child  with  all  these  openings  so  particularly  wide,  that  upon  the 
slightest  coughing  or  crying,  herniae  came  down  at  every  pos- 
sible point,  at  the  navel,  the  scrotum,  the  thigh,  and  in  the  sides 
of  the  abdomen,  all  at  once;  or,  as  one  tumour  was  reduced, 
another  arose. 

The  eifects  of  the  abdominal  muscles  in  moving  the  trunk 
cannot  be  mistaken.  The  recti  pull  the  ribs  downwards  in 
breathing,  flattening  the  belly,  and  bending  the  body  forwards. 
The  two  uBLiQUE  MUSCLES  of  One  side  acting,  turn  the  trunk 
upon  its  axis ; but  the  oblique  muscles  of  the  opposite  side 
acting,  co-operate  with  the  rectus  in  flattening  the  belly,  and, 
bending  the  body  ; and  the  transverse  muscles  tighten  the 
linea  alba,  so  as  to  give  effect  to  all  the  others ; and  particularly 
they  brace  the  sheath  of  the  recti  muscles,  so  as  to  give  them 
their  true  effect. 

CXLIX.  The  DiAPHRAGMA  is  a Greek  word,  translated 
inter-septum,  the  transverse  partition  betwixt  the  abdomen  and 
the  thorax,  the  midrilf;  but  it  is  not  merely  a transverse 
partition,  it  is  a vaulted  division  betwixt  the  thorax  and  abdo- 
men ; and  not  only  is  the  middle  raised  into  a vaulted  form, 
but  its  obliquity  is  such,  that  though  its  forepart  be  as  high  as 
the  sternum,  its  lower  and  back  part  arises  near  the  pelvis  from 
the  lowest  vertebra  of  the  loins. 

It  is  a circular  muscle,  which  is  fleshy  towards  its  borders, 
and  tendinous  in  the  centre  ; which  is  convex  towards  the 
thorax,  and  concave  towards  the  abdomen  ; becoming  plain, 
or  almost  so,  when  it  presses  against  the  abdominal  muscles 
in  drawing  the  breath  ; and  returning  to  its  convex  form,  when 
the  abdominal  muscles  re-act  in  pushing  it  back  into  the  thorax. 


!228 


MUSCLES  OF  THE  ABDOMEN, 


The  diaphragm  arises,  by  one  broad  fleshy  attachment  fronj 
all  the  borders  of  the  chest,  forming  the  upper  or  greater  mus- 
cle of  the  diaphragm  : and  it  arises  below,  by  many  small  ten- 
dinous feet  from  the  forepart  of  the  loins,  which  meeting, 
form  what  is  called  the  lesser  muscle  of  the  diaphragm.  1st, 
The  GREAT  or  upper  muscle  arises,  first,  from  under  the 
xiphoid  cartilage,  and  from  the  lower  surface  of  the  sternum. 
2dly,  From  all  the  false  ribs  ; from  the  cartilage  of  the  seventh, 
eigth,  and  ninth  ribs  ; and  from  the  bony  parts  of  the  tenth  and  (1 
eleventh  ribs,  and  from  the  tip  of  the  twelfth  rib.  All  these 
origins  are,  of  course,  fleshy  digitations  or  tongues  which  inter- 
mix with  those  of  the  transverse  muscle  of  the  abdomen.  3dly, 
From  the  tip  of  the  twelfth  rib  to  the  lumbar  vertebrae,  there 
is  a ligament  extended,  which,  going  like  an  arch  over  the 
psoas  and  quadratus  lunr;borum  muscles,  is  named  me  amentum 
ARCUATUM  ; and  from  this  another  part  still  of  the  great  mus- 
cle of  the  diaphragm  arises.  Thus,  the  upper  muscle  of  the 
diaphragm  has  four  chief  origins,  viz.  from  under  the  sternum 
and  xiphoid  cartilage ; from  all  the  false  ribs ; from  the  Jiga- 
mentum  arcuatum  ; and,  in  short,  from  all  the  borders  of  the 
chest,  from  the  xiphoid  cartilage  quite  round  to  the  vertebrae 
of  the  loins. 

2.  The  lesser  mulcle  of  the  diaphragm,  which  arises 
from  the  spine,  begins  by  four  small  slender  tendinous  feet  on 
each  side.  The  first  of  these,  the  longest  one,  arises  from  the  || 
second  vertebra  above  the  pelvis  : it  goes  from  the  flat  forepart 

of  its  body,  and  adheres  to  the  forepart  of  all  the  lumbar  ver- 
tebrae as  it  mounts  upwards.  The  second  rises  from  the  third 
vertebra,  but  farther  out  towards  the  side  of  the  vertebra.  The 
third  arises  from  the  side  of  the  fourth  vertebra.  And  the 
fourth  tendon  of  the  diaphragm  arises  from  the  transverse  pro- 
cess of  the  same  fourth  vertebra  of  the  loins.  But  indeed  we 
ought,  in  place  of  this  minute  demonstration,  to  say,  that  it 
arises  from  the  four  uppermost  lumbar  vertebrae  by  four  tendi- 
nous feel,  flat  and  glistening,  and  adhering  closely  to  the  shining 
ligament  with  which  the  bodies  of  the  vertebrae  are  strength- 
ened ; that  these  tendons  soon  join  to  form  two  strong  round 
fleshy  legs,  which  are  called  the  crura  diaphragmatis  ; of  which 
crura,  the  left  is  the  smaller  one  : and  these  crura  having 
opened  to  admit  the  aorta  betwixt  them,  and  then  joining,  mix- 
ing, and  crossing  their  fibres,  form  a fleshy  belly,  the  lesser  | 
muscle  of  the  diaphragm.  i 

3.  The  TENDON  in  the  centre  of  the  diaphragm  is  deter-  , 
mined  in  its  shape  by  the  extent  of  these  fleshy  bellies ; for  the 
great  muscle  above  almost  surrounds  the  central  tendon.  The 
smaller  muscle  below  meeting  it,  the  two  divisions  give  it  a 


AND  OF  THE  DIAPHRAGM. 


229 


pointed  form  behind  ; the  tendon  has  the  figure  of  a trefoil  leaf, 
or  of  the  heart  painted  upon  playing  cards.  The  middle  line 
of  this  tendinous  centre  is  fixed  by  the  membrane  which  di- 
vides the  thorax  into  two ; the  two  sides  go  upwards  into  the  two 
sides  of  the  chest,  each  with  a form  like  the  bottom  of  an  in- 
verted basin  : their  convexity  reaching  within  the  thorax,  quite 
up  to  the  level  of  the  fourth  true  rib  : the  proper  centre  of 
the  diaphragm  is  fixed  by  this  connection  with  the  mediasti- 
num, that  its  motion  might  not  disorder  the  action  of  the  heart, 
which  rests  upon  this  point,  and  whose  pericardium  is  fixed  to 
the  tendon  : but  the  convexity  of  either  side  descends  and  as- 
cends alternately  as  the  diaphragm  contracts,  or  is  relaxed ; so 
that  it  is  chiefly  these  convexities  on  either  side  which  are 
moved  in  breathing. 

Thus  is  the  diaphragm  composed  of  one  great  and  circular 
muscle  before  ; of  one  smaller  circular  muscle  behind  ; and  of 
the  triangular  tendon,  as  the  centre  betwixt  them  : and,  both 
in  its  fleshy  and  tendinous  parts,  it  is  perforated  by  several  ves- 
sels passing  reciprocally  betwixt  the  thorax  and  the  abdomen. 

First,  the  aorta,  or  great  artery  of  the  trunk,  passes  be- 
twixt the  crura  or  legs  of  the  diaphragm,  which,  like  an  arch, 
strides  over  it  to  defend  it  from  pressure.  The  thoracic  duct 
passes  up  here  also. 

Secondly,  The  cesophagus  passes  trough  the  diaphragm,  a 
little  above  this,  and  to  the  left  side  : its  passage  is  through  the 
lower  fleshy  belly,  and  through  the  most  fleshy  part  of  the 
diaphragm  : and  the  muscular  fibres  of  the  crura  diaphragma- 
tis  first  cross  under  the  hole  for  the  cesophagus ; then  surround 
it;  then  cross  again  above  the  hole;  so  that  they  form  the  fi- 
gure of  8 : and  the  (esophagus  is  so  apparently  compressed  by 
these  surroimding  fibres,  that  some  anatomists  have  reckoned 
this  a sort  of  spincter  for  the  upper  orifice  of  the  stomach. 

Thirdly,  The  great  vena  cava  goes  up  from  the  abdomen 
to  the  heart,  through  the  right  side  of  the  diaphragm  ; and  this 
hole  being  of  a triangular  form,  being  in  the  firm  tendon,  there 
is  no  danger  of  strangulation,  or  of  the  blood  being  impeded  in 
the  vein. 

The  tendon  is  composed  of  fibres  which  come  from  the  va- 
rious fasciculi  of  this  muscle,  meet  and  cross  each  other  with  a 
confused  interlacement,  which  Albinus  has  been  at  much  pains 
to  trace,  but  which  Haller  reports  much  more  sensibly  : “ In- 
tricationes  varia;  el  vix  dicendae ;”  irregular  and  confused,  cros- 
sing chiefly  at  the  openings,  and  especially  at  the  vena  cava, 
the  triangular  form  of  which  seems  to  be  guarded  in  a most 
particular  way. 

The  lower  surface  of  the  diaphragm  is  lined  with  the  peri- 


230  MUSCLES  OF  THE  ABDOMEN,  &C. 

tonaeum,  or  membrane  of  the  abdomen  ; and  the  upper  surface 
is  covered  with  the  pleura,  or  membrane  of  the  chest.  The 
hole  for  the  vena  cava  is  so  large  that  the  peritonajum  and 
pleura  meet,  and  nearly  touch  each  other  through  this  open- 
ing, all  round  the  vein. 

The  chief  use  of  the  diaphragm  is  in  breathing,  and  in  this 
office  it  is  so  perfect,  that  though  there  be  a complete  anchy- 
losis of  the  ribs  (as  has  often  happened),  the  person  lives  and 
breathes,  and  never  feels  the  loss.  The  diaphragm  is,  in  its 
natural  state,  convex  towards  the  thorax;  when  it  acts,  it  be- 
comes plain,  the  thorax  is  enlarged,  and,  by  the  mere  weight 
of  the  air,  the  lungs  are  unfolded,  and  follow  the  diaphragm. 
No  vacuum  is  ever  found  betwixt  the  diaphragm  and  the  lungs; 
but  the  lungs  follow  the  ribs  and  diaphragm  as  closely  as  if 
they  adhere  to  them  : and  indeed  when  they  do  adhere,  it  is 
not  known  by  any  distress.  So  we  draw  in  the  breath,  and 
when  the  abdominal  muscles  re-act,  the  diaphragm  yields,  goes 
back  into  the  thorax,  and  grows  convex  again,  by  which  we 
blow  out  the  breath  ; and  while  the  diaphragm  is  acting,  the 
abdominal  muscles  are  relaxed,  yield,  and  are  pushed  out, 
and  leave  the  ribs  free,  to  be  raised  by  their  levator  muscles. 
And  again,  when  the  abdominal  muscles  re-act,  the  dia- 
phragm in  its  turn  yields  so,  that  they  at  once  force  up  the 
diaphragm,  and  pull  down  the  borders  of  the  thorax,  assisting 
the  serrated  muscles  which  depress  the  ribs. 

There  is  also  in  every  great  function,  such  a wonderful  com- 
bination of  actions  conspiring  to  one  end,  as  cannot  be  even 
enumerated  here.  But  the  alternate  action  and  re-action  of 
of  the  abdominal  muscles  draws  in  and  expels  the  breath,  pro- 
motes the  circulation,  and  gently  agitates  the  bowels,  while 
their  more  violent  actions  discharge  the  f-tces  and  urine,  and 
assistthe  womb;  and  vomiting,  yawning,  coughing,  laughing,cry- 
ing,  hiccup,  and  the  rest,  are  its  stronger  and  irregular  actions. 
The  diaphragm  might  well  be  named  by  Haller,  “Nobilis- 
simus  post  cor  musculus.”  And  Buffon,  who  affected  the  cha- 
racter of  anatomist  with  but  little  knowledge  of  the  human 
body,  might  mistake  its  central  tendon  for  a nervous  centre, 
the  place  of  all  motions,  and  almost  the  seat  of  the  soul.  For 
the  ancients  confounded  the  names  and  ideas  of  tendon  and 
nerve.  And,  in  sickness  and  oppression,  lowness  and  sighing, 
in  w'eeping  or  laughing,  in  joy  or  in  fear,  all  our  feelings  seem 
to  concentrate  in  this  part. 


( 231  ) 


CHAP.  VII. 


THE  MUSCLES  OF  THE  PARTS  OF  GENERATION, 
AND  OF  THE  ANUS,  AND  PERINEUM. 

The  muscle  of  tbe  parts  of  generation  follow  the  division  of 
of  the  abdominal  muscles  more  naturally  than  any  other. 

The  ERECTOU,  PENIS  is  a small  and  slender  muscle,  which 
goes  over  the  crus  penis,  and  braces  it  back  to  the  pubes. 
The  erectoi’es  are  supposed  (by  pressing  tbe  penis  against  the 
pubis)  to  compress  the  great  vein,  and  so  cause  erection.  The 
EJACULATOK  sEMiNis  is  a Riusclc  wbich  surrounds  all  the  bulb 
of  the  urethra,  and  acts  by  a sort  of  subsultus  in  discharging  the 
last  drops  of  the  urine,  and  in  throwing  out  the  semen.  And 
tbe  TRANsvERSALis  perinid,  which  goes  across  the  perinaeura, 
belongs  rather  to  the  anus  than  to  the  penis. 

The  SPHINCTER  ANi  is  a circular  bundle  of  fibres,  which  sur- 
rounds the  orifice  of  the  anus,  and  contracts  it ; and  the  leva- 
tor ani  is  a flat  thin  muscle,  which  lines  the  pelvis,  surrounds 
the  rectum  like  a funnel,  and  being  fixed  round  the  margin  of 
the  anus,  raises  it  up;  and  the  coccvciEcs  is  but  a part  of  it. 
The  DETRUSOR  DRiN^  is  the  muscular  coat  of  the  bladder,  and 
the  SPHINCTER  VEsic\«:  is  not  easily  distinguished  from  the  de- 
trusor urinse,  being  but  the  fibres  of  it,  only  thicker  and  stronger 
at  tbe  lower  and  narrower  part  of  the  bladder. 

The  penis  is  composed  of  two  ci’ura,  or  cavernous  bodies, 
which  arise  from  the  branch  of  each  os  ischium,  which  soon 
meet  to  form  the  body  of  the  penis ; and  of  the  corpus  caver- 
nosum  urethra;,  which  surrounds  the  urethra,  is  attached  to  no 
bone,  but  begins  just  before  the  circle  of  tbe  anus,  by  a bulg- 
ing,. which  is  called  the  bulb  of  the  urethra;  and  the  erector 
penis  lies  along  the  crura,  to  draw  them  back  to  the  pubes ; 
and  the  ejaculator  surrounds  all  the  bulb,  and  acts  in  expelling 
the  semen  or  the  last  drops  of  urine. 

CL.  The  ERECTOR  PENIS  is  a delicate  and  slender  muscle, 
about  two  inches  in  length.  It  lies  along  the  face  of  tbe  crus 
penis  on  each  side.  And  when  the  crura  penis  are  inflated, 
the  erectors  are  seen  of  their  proper  length  and  form.  The 
erector  of  each  side  rises  by  a slender  tendon  from  the  tube- 
rosity of  the  os  ischium.  It  goes  fleshy,  thin,  and  flat,  over 
the  crus  penis,  like  a thin  covering.  It  ends  in  a delicate  and 
flat  tendon,  upon  tbe  crus  penis,  about  two  inches  up ; and  the 
tendon  is  so  thin  and  delicate,  that  it  is  hardly  to  be  distin- 
guished from  the  membrane  of  the  cavernous  body. 


MUSCLES  OF  THE  PARTS  OF 


232 

The  erectors  lying  thus  on  the  sides  of  the  penis,  have  been 
called  coLATEKALES  PENIS  OP  1 scH lO-CAVERNOsi  frona  their 
origin  in  the  ischium,  and  their  insertion  into  the  cavernous 
bodies. 

CLI.  The  TRANSVERSALis  perina;i  is  often  named  trans- 
versalis  penis;  but  its  origin  being  in  the  tuberosity  of  the  os 
ischium,  by  a delicate  tendon,  and  its  insertion  into  the  very 
backmost  point  of  the  bulb  of  the  urethra,  where  it  nearly 
touches  the  anus,  and  where  there  is  a meeting  of  severd 
muscles,  its  course  is  directly  across  the  perinaeum,  and  its  re- 
lation to  the  perinaeum  and  anus  is  very  direct  and  evident, 
while  its  relation  to  the  penis  is  rather  doubtful.  Often  there 
is  a second  muscle  of  the  same  origin  and  insertion,  running 
like  this,  across  the  perinaeum,  named  transversalis  PERiNiEi 

ALTER.* 

This  transverse  muscle  may,  by  bracing  up  the  bulb  to  the 
arch  of  the  pubis,  have  some  effect  in  stopping  the  vein  on  the 
back  of  the  penis,  and  so  producing  erection  ; but  its  chief  use 
must  be  in  preventing  the  anus  from  being  too  much  protruded 
in  discharging  the  faeces,  and  in  retracting  it  when  it  is  already 
protruded. 

CLII.  The  EJACULATOR  muscle  is  not  a single  muscle,  as  it 
is  often  described.  It  is  manifestly  a pair  of  muscles  surround- 
ing the  whole  of  the  bulb  of  the  urethra.  They  arise  on  each 
side  from  the  side  of  the  bulb,  and  crus  of  the  penis,  and  from 
the  triangular  ligament  of  the  urethra.  From  their  arising 
from  this  ligament,  they  have  been  frequently  described  as 
arising  from  the  ramus  of  the  pubes.  There  is  along  the  lower 
face  of  the  bulb  a white  and  tendinous  line,  corresponding 
with  tbe  outward  line  or  seam  of  the  perinaeum.  This  line 
distinguishes  the  bellies  of  the  two  muscles,  and  is  formed  by 
their  tendinous  insertions ; or  sometimes  this  central  line  is 
considered  as  the  origin  of  the  muscle  : in  that  case,  the  fibres 
of  each  side  surround  their  proper  half  of  the  bulb  with  circu- 
lar fibres,  winding  obliquely  round  the  bulb ; and  each  muscle 
ends  in  its  separate  tendon,  which  is  delicate  and  small,  and 
which,  leaving  the  bulb  of  the  urethra,  turns  off  obliquely  to 
the  side,  so  that  the  tendon  of  each  side  goes  out  flat  and  thin 

* There  is  great  irregularity  in  this  muscle.  There  is  very  frequently  a slip  called  trans- 
versalis  alter,  which,  however,  would  be  better  named  obliquus.  In  some  bodies  the  trans- 
versalis  is  hardly  perceptible,  while  in  otlrers  it  is  very  strong ; there  is  also  a great  variety 
in  the  size  of  it  on  comparing  the  two  sides  of  the  same  body ; thus  we  see  frequently  in  Las- 
cars and  N egroes,  that  on  one  side  there  is  a very  large  muscle,  while  on  the  other  there  is  a 
small  transversalis,  and  a large  obliquus. 

W e n>ay  also  frequently  see  a muscle,  the  transversalis  profundus ; it  has  exactly  the  same 
origin  and  insertion  with  the  other,  but  lies  deeper.  At  first  view  it  appears  to  be  part  of  the 
levator  ani,  but  tbe  fibres  run  directly  across,  while  those  of  the  levator  run  in  a descending 
direction. 


GENERAGTION,  anus,  and  PERINiEUIVr.  233 

open  the  crus  penis  of  its  own  side,  a little  higher  than  the  in- 
sertion of  the  erector  penis.  We  know  and  feel  its  convulsive, 
involuntary  action  in  throwing  out  the  seed ; and  we  are  con- 
scious that  we  use  it  as  a voluntary  muscle  in  emptying  the 
urethra  of  the  last  drops  of  urine. 

CLIII.  The  SPHINCTER  ANi  muscle  is  abroad  circular  band 
of  fibres,  which  surrounds  the  anus.  It  arises  from  the  point 
of  the  os  coccygis  behind.  It  sends  a neat  small  slip  forwards, 
by  which  it  is  attached  to  the  back  part  of  the  ejaculator  mus- 
cle ; but  the  great  mass  of  the  muscle  is  inserted  into  the  com- 
mon angle  of  the  union  of  the  ejaculator,  transversales,  and 
this  muscle.  It  is  of  a regular  oval  form,  and  is,  for  a verj'" 
obvious  reason,  stronger  in  man  than  in  animals.  Some  choose 
to  enumerate  two  sphincter  muscles,  of  which  this  is  the  ex- 
ternal, or  cutaneous ; and  what  they  describe  as  the  internal 
one,  is  merely  the  circular  fibres,  or  muscular  coat  of  the 
intestine,  strengthened  a little  towards  the  anus,  but  not  a dis- 
tinct muscle.  Its  effect  is  to  shut  the  anus. 

CLIV.  The  LEVATOK  ani  muscle  is  described  as  a pair  of 
muscles,  one  from  each  side  ; but  it  is  properly  one  broad  and 
thin  muscle,  which  arises  from  the  internal  surface  of  all  the 
forepart  of  the  pelvis,  and,  from  its  breadth,  it  has  been  named 
MuscuLDs  ANI  LATUS.  »It  continues  its  origin  from  the  inter- 
nal surface  of  the  pubes,  from  the  edge  of  the  foramen  thy- 
roideum,  from  the  thin  tendinous  sheath  that  covers  the  ob- 
turator internus  and  coccygeus  muscles,  and  from  the  body  and 
spine  of  the  os  ischium.  It  grows  gradually  smaller,  as  it 
goes  downward  to  surround  the  anus.  So  it  is  inserted  into 
the  circle  of  the  anus,  into  the  point  of  the  os  coccygis,  and  is 
mixed  with  the  sphincter  ani  muscle.  The  whole  pelvis  is 
lined  with  it  like  a funnel,  or  inverted  cone,  the  wider  part 
representing  its  origin  from  the  pelvis,  the  narrower  part  its 
insertion  into  the  anus.  The  whole  bladder  is  surrounded, 
and  covered  by  this  muscle  ; the  urethra  passes  through  a split 
in  its  fibres,  and  no  operation  of  lithotomy  can  reach  the  blad- 
der from  below,  without  cutting  through  this  muscle.  It 
raises  the  anus,  and  at  the  same  time  dilates  it,  opening  tbe 
anus  for  the  passage  of  the  f.cces,  and  supporting  it,  so  as  to 
prevent  its  being  protruded.  Thus,  it  is  not  for  shutting  the 
anus,  as  some  have  supposed,  but  is  the  direct  antagonist  of 
the  sphincter  ani  muscle.  By  enclosing  the  bladder,  the  le- 
vator ani  acts  upon  it  also  ; for  the  neck  of  the  bladder  pass- 
ing through  a slit  in  its  fibres,  while  the  levator  ani  is  acting, 
this  slit  is  drawn,  jfis  it  were,  round  the  neck  of  the  bladder, 
and  so  the  urine  is  for  the  time  prevented  from  flowing.  It  is 
as  a sphincter  to  the  bladder,  which  prevents^  our  passing  the 

VOE.  I.  G g 


234 


MUSCLES  OF  THE  PARTS  OF 


urine  and  fseces  at  the  same  moment.  By  surrounding  the 
lower  part  of  the  bladder,  and  enclosing  the  prostrate  gland, 
and  the  vesicula-  seminales,  which  lie  upon  the  back  of  the 
bladder,  this  muscle  affects  these  parts  also,  and  is  perhaps  the 
only  muscle  which  may  be  supposed  to  empty  the  vesiculie, 
or  to  compress  the  gland,  pulling  upwards  at  the  same  time, 
so  as  to  press  the  back  of  the  penis  against  the  pubes,  to  main- 
tain the  erection,  and  to  assist  the  accelerator  muscles.  By 
enclosing  the  bladder,  vesicul  , prostrate  and  anus,  this  muscle 
produces  that  sympathy  among  the  parts,  which  is  often  very 
distressing,  as  in  gonorrhoea,  the  stone  in  the  bladder,  consti- 
pation, piles,  and  other  diseases  of  these  parts;  for  piles,  con- 
stipation, or  any  cause  which  may  excite  the  action  of  the  le- 
vator muscles,  will  cause  erections,  a desire  to  pass  the  urine; 
and  an  obstruction  in  the  discharge  of  it.*^ 

CLV.  The  MUscuLus  coccyga;us  is  a thin,  flat  muscle, 
which  arises  by  a narrow  point  from  the  inside  of  the  pelvis, 
at  the  spine  of  the  os  ischium;  is  implanted,  expanded  and 
fleshy,  into  the  whole  length  of  the  os  coccygis ; can  be  useful 
only  by  pulling  up  the  point  of  the  os  coccygis ; which  is  just 
equivalent  to  raising  the  circle  of  the  anus;  so  that  from  every 
circumstance  of  its  form  and  use,  it  might  be  fairly  enough 
described  as  being  merely  the  back  part  of  the  levator  ani 
muscle. 

The  perinasum,  where  the  bulb  begins,  is  the  point  int® 
which  ail  the  muscles  are  united ; for  the  ejaculator  muscle, 
and  the  sphincter  ani  muscle,  touch  at  the  beginning  or  point 
of  the  bulb  : and  a small  pointed  slip  of  the  sphincter  ani, 
going  upon  the  bulb,  connects  them  firmly  together.  The 
transversales  perincei  come  across  the  perinaeum  from  either 
side  ; and  the  levator  ani  muscle  comes  down  to  meet  the 
sphincter,  so  that  the  sphincter  ani,  the  levator  ani,  the  trans- 
versalis  perinaei,  and  the  ejaculator  muscles,  all  meet  in  one 
point,  viz.  the  back  of  the  bulb.  They  secure  the  perinaeum, 
and  support  the  heavy  viscera  of  the  abdomen ; if  they  be 
unskilfully  cut  in  performing  lithotomy,  it  will  be  difiicult  to 
extract  the  stone.  In  that  operation,  the  incision  passes  by 
the  side  of  the  anus,  and  on  the  inside  of  the  tuber  ischii  ; 
and  our  knife  accordingly  cuts  clean  across  the  transverse 
muscles,  which  stand  as  a bar  across  the  perinaeum  ; it  passes 
by  the  side  of  the  erector  muscle,  need  not  touch  it,  or 

* There  is  a muscle  described  Iiy  Mr.  Wilson,  as  a levator,  or  compressor  urethrse.  The 
origin  of  tliis  muscle  is  from  the  arch  of  the  pubes,  and  its  fibres  run  round  the  membranous 
part  of  the  urethra,  being  inserted  on  the  lower  part  into  each  other : it  is  situated  between 
the  Cowper’s  gland  and  the  levator  ani,  being  separated  from  tlie  I3st  muscle  by  a thin  fascia, 
and  some  small  veins.  In  order  to  make  out  this  muscle  distinctly,  and  with  as  large  a ten.’ 
dim  as  Mr.  Wilson  describes  it,  it  is  necessary  to  sacrifice  several  of  tlie  fascia>. 


GENERATION,  ANUS,  AND  PERINEUM.  235 

Couches  it  slightly,  and  by  a sort  of  chance  : it  must  not  touch 
the  ejaculator  muscle  ; for  whoever  says  he  cuts  the  ejacu- 
lator  cuts  too  low,  and  performs  his  operation  ill.*  After  the 
first  incision  we  get  deep  into  the  pelvis,  and  cut  the  levator 
ani.  The  surgeon  does  not  observe  these  muscles,  on 
account  of  any  danger  which  may  attend  wounds  of  them, 
hut  takes  them  as  marks  for  the  true  place  of  his  incision; 
and  a good  operator  will  be  careful  to  have  them  fairly  cut, 
that  they  may  be  no  hindrance  to  the  extraction  of  the  stone.f 
We  find  of  course  a difference  in  the  muscles  in  the  female 
perineum.  There  is  an  erector  clitoridis,  which  has  the 
same  origin  as  in  the  male,  and  it  is  inserted  into  the  crura 
clitoridis,  in  the  same  manner  that  the  erector  penis  is  in- 
serted into  the  crura  penis.  The  next  muscle  is  the  sphincter 
vaginre,  which  is  a large  muscle  taking  an  origin  from  the 
sphincter  ani  and  posterior  side  of  the  perineum  ; it  is  in- 
serted into  the  union  of  the  crura  clitoridis.  We  find  like- 
wise a transversalis  which,  though  taking  the  same  origin  as 
in  the  male,  is  a very  small  muscle  ; its  insertion  is  into  the 
union  between  the  sphincter  vagiute  and  sphincter  ani : in  the 
two  next  muscles,  viz.  sphincter  ani  and  levator  ani,  there  is 
no  difference,  except  that  they  are  attached  to  the  vagina 
instead  of  the  penis. 


CHAP.  VIII. 

MUSCLES  OF  THE  THIGH,  LEG,  AND  FOOT. 

MUSCLES  MOVING  THE  THIGH-BONE. 

The  muscles  belonging  to  the  thigh-kone  arise  all  from  the 
pelvis  or  trunk.  The  psoas  magnus,  and  iliacus  internes, 
come  from  within  the  pelvis,  and  its  forepart,  and  passing 
under  the  femoral  ligament,  go  down  to  be  implanted  into 
the  trochanter  minor ; and  by  this  obliquity  of  tbeir  insertion, 
they  turn  the  toes  outwards,  and  bend  the  thigh.  Other 

* Those  anatomists  who  desci  ibe  the  origin  of  the  ejaculator  to  be  from  the  ramus  isehii 
object  to  this. 

t The  detrusor  urin»  is  but  the  mascular  coat  of  the  b'adder  ; the  sphincter  vesie®  ia 
but  a denser  fasciculus  of  tliis  common  coat  of  the  bladder.  I should  no  more  think  of 
describing  them  here  than  of.describing  the  coats  of  the  intestines  or  stomach.  These 
muscles  of  internal  parts,  with  the  muscles  of  the  internal  ear,  &c.  1 reserve  for  (lio^. 
^ooks  which  describe  the  organs  and  viscera. 


MUSCLES  MOVING  THE  THIGH-BONE. 


2SG 


muscles  come  from  the  lower  and  forepart  of  the  pelvis,  a? 

the  I’ECTINALIS,  TRICEPS,  and  OBTURATOR  EKTEUNUS,  which 

arise  from  the  arch  of  the  os  pubis,  and  go  down  to  be  im- 
planted into  the  linea  aspera  and  lesser  trochanter ; and,  they 
pulling  the  thigh  towards  the  body,  are  called  the  adductors. 
Others  arise  from  the  sacrum  and  back  part  of  the  pelvis,  as 
the  GLUTiEi,  which  coming  directly  forwards  to  be  implanted 
into  the  greater  trochanter,  pull  back  the  thigh  ; and  a fourth 
set  coming  also  from  the  internal  surface  of  the  pelvis ; viz. 
the  OBTUKATOR  INTERN  US  and  the  pyramidalis  come  out 
through  the  back  opening,  turn  round  the  pelvis,  as  round  a 
pulley,  and  roll  the  thigh,  and  draw  it  back.  This  completes 
the  catalogue  of  those  muscles  which  move  the  thigh, 

1.  The  PSOAS  MAGNUS,  ILIACUS  INTERNUS,  PECTINEUS, 
TRICEPS,  OBTUKATOR  EXTEHNUs,  wliich,  coming  froiD  before, 
are  inserted  into  the  line  of  the  minor  trochanter,  and  bend 
the  thigh. 

2.  The  GLUTEI,  GEMINI,  PYRIFORMIS,  OBTURATOR  INTER- 
NUS, and  Q.UADRATUS,  which  come  from  behind,  are  implanted 
into  the  line  of  the  great  trochanter,  and  extend  the  thigh ; 
and  it  hardly  need  be  remembered,  that  as,  when  the  arms 
being  fixed,  their  muscles  raise  the  weight  of  the  body,  as  in 
climbing  or  in  turning  over  a bar,  by  grasping  with  the  hands  ; 
so  the  muscles  of  the  thigh  move  that  thigh  only  which  is 
loose,  and  free  from  the  weight  of  the  body,  while  the 
muscles  of  the  other  thigh,  which  is  fixed  by  the  weight  of  the 
body,  move  not  the  thigh,  but  the  trunk  upon  the  thigh  ; so 
that  our  walking  is  performed  not  so  much  by  the  muscles  of 
the  thigh  moving  the  limb,  as  by  their  moving  the  pelvis,  (z.  e.) 
rolling  the  trunk  upon  the  limb. 


MUSCLES  MOVING  THE  THIGH. 


1.  THE  THIGH  IS  MOVED  BACKWARDS  AND  OUTWARDS, 

By  the  glutaeus  inaximus,  i which  is  I linea  aspera, 

niedius,  > implanted  J trochanter  major, 

minimus,  5 into  the  ^ top  of  trochanter. 


2.  THE  THIGH  IS  MOVED  BACKWARDS,  AND  ROLLED  UPON  IT 

AXIS, 


which  is 


By  the  pyryformis, 

Lturator  extemus,  J 

• uiternus,  \ 

quadratus,  J 


; root  of  the  trochanter. 


betwixt  the  trochanters. 


MUSCLES  MOVING  THE  THIGH-BONE. 


237 


3.  THE  THIGH  IS  MOVED  FORWARDS  AND  INWARDS, 
By  the  oioor, 


Fascialis.  I begin  with  this  muscle,  as  it  is  necessary  in 
the  dissection.  The  thigh  is  enclosed  in  a very  strong  sheath, 
which,  like  that  of  the  arm,  sends  down  among  the  muscles 
strong  tendinous  septa  or  partitions ; and  the  muscles  are 
enclosed  in  these  septa,  and  the  great  muscles  of  the  leg  are 
supported  by  it,  in  their  strong  and  continual  actions.  The 
tendinous  fascia  of  the  thigii  arises  chiefly  from  .the  spine  of 
the  ilium,  partly  (over  the  groin)  from  the  external  oblique 
muscle  of  the  abdomen.  Every  fascia  has  something  added 
by  each  muscle,  and  takes  a new  increase  and  adhesion  at 
each  bone  which  it  passes.  It  is  always  strengthened  by  ad- 
hesions to  joints,  and  comes  down  from  them  thicker  upon 
the  muscles  below ; and  so  this  fascia  of  the  thigh,  which 
arises  chiefly  from  the  spine  of  the  ilium,  descends,  covering 
all  the  muscles  of  the  thigh  : it  sends  partitions  down  to  the 
linea  aspera  and  trochanters ; it  has  a new  adhesion,  and  a 
new  source  of  tendinous  fibres  at  the  knee  ; it  adheres  most 
remarkably  at  the  inner  side  of  the  tibia,  and  then  descends 
to  the  calf ; it  covers  all  the  leg,  and  is  again  re-inforced  at  the 
ancle  ; and  this  I believe  to  be  a juster  history  than  the  com- 
mon idea  of  making  it  an  expansion  of  the  small  tendon  of 
the  small  muscle,  which  I am  now  to  describe  ; for  the  fascia 
is  too  essential  to  the  strength  of  the  leg,  and  would  be  found 
there,  though  this  muscle  were  away,  as  is  the  case  with  the 
palmar  expansion. 

This  fascia  rightly  consists  of  two  plates ; one  is  that  which 
comes  down  from  the  crest  of  the  ilium,  and  from  the  muscles 
of  the  belly ; the  other,  that  which  arises  purely  from  the  ten- 
don of  themusculus  fascialis,  and  which  is  at  the  same  time  con- 
nected with  the  capsular  ligament  of  the  femur,  and  with  the 
trochanter ; and  so  the  muscle  lies  betwixt  the  two  plates  of 
the  fascia;  and  as  the  fascia,  at  this  part,  takes  at  least  a re- 
inforcement from  the  capsular  ligament  and  from  about  the 
trochanter  major,  the  fascialis  muscle  may  be  said  to  be  insert- 
ed into  the  trochanter. 

So  this  great  tendinous  fascia  has  these  connections : the 
crest  of  the  ilium  ; the  ligament  of  Paupart,  at  the  rim  of  the 
belly ; the  crest  and  arch  of  the  os  pubis ; the  tuber  ischii,  and 
so  back  along  the  coccyx,  to  the  ridge  and  processes  of  the 


238 


MUSCLES  MOVING  THE  THIGHtBONE. 


sacrum;  the  ligament  of  the  joint,  the  great  trochanter;  and 
the  linea  aspera,  all  the  way  down  to  the  knee,  where  its  last 
adhesion  is  very  strong,  and  from  whence  it  comes  off  again, 
much  strengthened. 

It  is  thicker  on  the  outer  side  and  back  part,  and  very  thin 
on  the  inner  side  of  the  thigh  ; and  it  dives  with  perpendicular 
divisions  among  the  muscles  of  the  thigh. 

CLVI.  The  FAsciALis  Mcsc!  K. — The  muscle  is  named  ten- 
sor vagin.j  femoris.  It  arises  from  the  upper  spinous  process 
ol’  the  ilium,  (/.  e.)  from  the  forepart,  or  very  point  of  its  spine, 
by  a tendon  of  about  an  inch  in  length.  It  is  very  small  at  its 
origin,  and  at  its  termination.  It  is  thick  and  fleshy  in  the 
middle,  swelling  out;  it  extends  downwards,  and  obliquely  back- 
wards, airnust  to  the  middle  of  the  thigh,  and  there  it  termi- 
nates obliquely,  betwixt  the  two  lamellas  of  the  membrane  to 
which  it  belongs. 

Its  use  is  chiefly  as  an  ahductor,  and  to  make  the  fascia 
tense,  to  prepare  the  muscles  for  strong  action ; and  perhaps, 
by  its  adhesions  about  the  trochanter,  it  may  have  some  little 
effect  in  rolling  the  thigh,  so  as  to  turn  the  toes  inwards,  and 
oppose  the  Gemini. 

CLVII.  Psoas  magxus. — This  and  the  following  muscle 
come  from  within  the  body  to  move  the  thigh  forwards.  This 
is  a very  long  and  fleshy  muscle,  of  considerable  strength,  of 
constant  use,  perpetually  employed  in  moving  the  thigh  for- 
ward or  in  supporting  the  pelvis  upon  the  thigh-hone,  so  as  to 
preserve  the  equilibrium  of  the  body. 

It  is  named  from  the  psoas  lumbps  ; is  a large  round  mus- 
cle, very  strong,  of  great  length,  filling  up  all  the  space  upon 
either  side  of  the  spine,  and  bounding  the  pelvis  at  its  side.  It 
comes  from  under  the  ligamentum  arcuatum  of  the  diaphragm; 
for  it  arises  first  by  its  uppermost  head  from  the  last  vertebra 
of  the  back,  then  successively  from  each  of  the  vertebrae  of  the 
loins  It  sticks  close  to  the  lumbar  vertebrae  ; for  it  arises  not 
only  from  the  transverse  processes  but  from  the  sides  of  the 
bodies.  These  heads  do  not  appear,  for  they  are  covered  by 
the  body  of  the  muscle,  which  goes  down  thick  and  round,  till 
it  reaches  the  sacro  iliac  symphyisis,  and  then  being  united  to 
the  internal  iliac  muscle,  they  descend  through  Paupart  s liga- 
ment. 

CLVIII.  The  psovs  parvus  does  not,  like  this,  belong  to 
the  thigh,  but  is  a muscle  of  the  loins,  which  arises  along  with 
this  one  from  the  last  vertebra  of  the  back,  and  the  first  of  loins. 

It  is  a small  and  delicate  muscle,  ends  in  a slender  tendon, 
which  goes  down  by  the  inner  side  of  the  great  psoas,  but  does 
not  go  out  of  the  pelvis  along  with  it : it  stops  short,  and  is  im- 


Muscles  moving  the  thigh-bone.  239 


planted  into  the  brim  of  the  pelvis,  into  the  os  ilium  near  the 

?lace  of  the  acetabulum  : it  bends  the  spine  upon  the  pelvis. 

"his  muscle  is  more  regular  in  the  monkey  : in  the  dog  it  is 
seldom  wanting.  It  is  said  to  be  more  frequently  found  in 
women  than  in  men  ; in  both,  it  often  is  not  to  be  found  : b-ut 
sometimes,  in  strong  and  big  men,  three  psoas  muscles  have 
been  found. 

CLIX.  The  iLiAcus  internus  is  a thick,  very  fleshy,  and 
fan-like  muscle,  which  occupies  the  whole  concavity  of  the  os 
ilium. 

Its  origin  is  from  the  internal  lip  of  the  crista  ilii  and  trans- 
verse process  of  the  last  lumbar  vertebrae  : it  adheres  to  all  the 
concave  surface  of  that  bone,  down  to  the  brim  of  the  pelvis ; 
to  the  forepart  of  the  bone  under  the  spinous  process ; and  to 
a part  also  of  the  capsular  ligament  of  the  joint : all  its  radiated 
fibres  are  gathered  together  into  a tendon  at  the  ligament  of 
Paupart.  This  tendon  is  longer  on  the  lower  than  on  the  up- 
per surface  : for  below,  it  slides  on  the  pubis  as  upon  a pulley, 
and  continues  tendinous  that  it  may  bear  the  friction ; but 
above  itis  unconnected,  or  it  is  connected  only  by  loose  cellular 
substance  j and  there  it  is  quite  fleshy.  Just  under  the  liga- 
ment, the  two  tendons  are  joined,  whence  they  bend  obliquely 
round,  to  be  implanted  into  the  lesser  trochanter. 

The  psoas  magnus  and  iliacus  internus  are  tw'o  very  powerful 
muscles.  Their  chief  use  is  to  bend  the  thigh,  and  more  pe- 
culiarly of  the  lumbar  one  to  support  the  body.  The  great 
blood  vessels  come  down  along  with  these  two  muscles  : the 
muscles  and  vessels  are  both  surrounded  with  loose  cellular 
substance ; matter  often  forming  behind  the  abdomen,  round 
the  psoas  muscle,  is  named  the  psoas  abscess,  and  penetrating 
under  Paupart’s  ligament,  bursts  in  the  thigh  at  last  and  is 
commonly  fatal. 

CLX.  The  PECTiNEus  or  pectinalis,  so  named  from  its 
arising  at  the  pecten  or  os  pubis,  is  a broad  flat  square  muscle  : 
it  lies  along-side  of  the  last  described  muscles,  and  is  inserted 
with  their  common  tendon.  It  arises  flat  and  fleshy  from  that 
part  of  the  os  pubis  which  is  bbunded  on  the  upper  part  by  the 
linea  ileo  pectihea,  and  on  the  low’er  by  a ridge  running  from 
the  tuberous  angle  of  the  pubes  to  the  upper  part  of  the  aceta- 
bulum, and  is  implanted  into  the  linea  aspera,  immediately  be- 
low the  trochanter  minor,  by  a tendon  flat  and  long,  pretty 
nearly  of  the  same  extent  and  shape  with  its  origin. 

This  muscle  lies  immediately  under  the  skin  and  fascia  lata; 
and  by  its  bending  round  under  the  thigh-bone,  it  has  three 
actions ; to  close  the  knees  together ; to  pull  the  thigh  forward; 
to  perform  rotation,  turning  out  the  toe;  and,  in  certain  posi- 


240  MUSCLES  MOVING  THE  THIGH-BONE. 

tions  of  the  limb,  it  will  pull  the  thigh  back,  assisting  the  exten- 
sor muscles. 

CLXI.  The  TRICEPS  femobis  is  a broad  flat  muscle,  with 
three  heads,  arising  from  the  os  pubis,  and  inserted  into  the 
whole  length  of  the  linea  aspera  down  to  the  condyle,  and 
serving  for  pressing  the  knees  together,  or  bringing  the  thigh 
forwards. 

The  triceps  consists  of  three  beads,  which  lie  in  different 
layers,  one  above  the  other ; and  have  so  little  connection 
among  themselves,  that  they  have  been  more  commonly,  and 
I think  properly,  described  as  three  muscles.  These  three 
parts  of  the  muscle  are  indeed  for  one  common  use : but  they 
are  of  very  different  forms ; for  they  do  not  even  lie  on  the 
same  plane  : one  is  long,  another  shorter  by  one  half,  a third 
longer  than  both  the  other  two  ; so  that  they  have  been  com- 
monly described  under  the  names  of  adductor  primus  or 
LONGUS  ; adductor  SECUNDUS  or  BREVIS  ; adductor  TERTIUS 
or  MAGNUS. 

1.  The  ADDUCTOR  LONGUS  is  the  uppermost  layer;  its  bor- 
der (for  it,  like  the  pectinalis,  is  a flat  muscle,)  ranges  with  the 
border  of  the  pectinalis.  It  arises  from  the  upper  and  forepart 
of  the  pubis  and  the  ligament  of  the  symphysis  by  a short 
roundish  tendon,  very  strong  ; it  swells  into  a thick  fleshy  bel- 
ly, not  round,  but  flattened  ; the  belly  grows  flatter  as  it  goes 
down  towards  the  thigh-bone  ; it  ends  in  a flat  and  short  ten- 
don, which  is  inserted  into  the  linea  aspera  in  all  its  middle 
part,  viz.  about  four  inches.  Thus,  the  muscle  is  of  a trian- 
gular form,  with  its  base  in  the  linea  aspera,  and  its  apex  on  the 
os  pubis.  Its  head  or  origin  lies  betwixt  the  pectinalis  and  the 
gracilis  : its  upper  edge  ranges  with  the  pectinalis ; its  lower 
edge  lies  upon  the  triceps  raagnus.  It  is  called  longus,  because 
it  is  longer  than  the  next  muscle. 

2.  The  ADDUCTOR  BREVIS  lies  Under  the  adductor  longus, 
and  is  of  another  layer  of  muscles ; for  as  the  first  layer  con- 
sists of  the  pectinalis,  triceps  longus,  and  gracilis,  this  layer 
consists  of  the  obturator  externus,  triceps  brevis,  and  triceps 
magnus.  The  triceps  brevis  is»exceedingly  like  the  former,  in 
rising  near  the  symphysis  pubis,  by  a thick  and  flattened  tendon, 
swelling  like  it  into  a strong  fleshy  belly ; like  it,  it  grows  flat, 
and  is  inserted  by  a short  flat  tendon  into  the  inner  trochanter 
and  linea  aspera.  But  it  differs  in  these  points  ; that  it  is  less 
oblique,  for  this  muscle  being  shorter,  goes  more  directly  across 
betwixt  the  ffelvis  and  the  thigh  : that  it  is  placed  higher  than 
the  last,  so  that  whereas  the  layers  are  inserted  into  the  middle 
of  the  thigh-bone,  this  one  is  inserted  into  the  lesser  trochanter, 
and  only  the  upper  part  of  the  linea  aspera;  and  the  triceps 


MUSCLES  MOVING  THE  THIGH-BONE., 


241 


longus  is  a superficial  muscle,  while  this  is  hidden  under  it, 
and  behind  it.  The  longus  takes  its  rise  from  the  very  crest  of 
the  os  pubis ; this  takes  its  origin  from  the  forepart  of  the  os 
pubis,  from  the  limb  just  under  the  crest,  so  as  to  be  imme- 
diately under  tlie  head  of  the  longus. 

3.  The  ADDUCTOR  MAGNUS,  the  third  head  of  the  triceps,  is 
a very  long  and  flat  muscle,  lying  behind  the  other  heads.  It 
arises  by  a short  tendon,  just  under  the  tendon  of  the  adductor 
brevis ; it  continues  to  have  a fleshy  origin  all  down  to  the 
ramus,  and  to  the  tuber  ischii,  {i.  e.)  from  the  flat  edge  of  the 
thyroid  hole.  From  this  broad  origin,  it  goes  to  be  implanted 
into  the  thigh-bone  the  whole  length  of  the  linea  aspera,  its 
fibres  having  various  degrees  of  obliquity,  according  to  their 
insertion,  for  the  uppermost  fasciculi  go  almost  directly  across, 
to  be  inserted  flat  into  the  upper  part  of  the  linea  aspera;  the 
succeeding  fasciculi  go  more  and  more  obliquely  as  they  de- 
scend, the  lower  part  of  the  muscle  following  that  rough  line 
which  leads  to  the  condyle,  and  the  last  fibres  of  all  are  im- 
planted,-by  a tendon  of  considerable  length,  into  the  condyle 
itself.  This  adductor  magnus  makes  as  it  were  a flat  partition 
betwixt  the  fore  and  the  back  parts  of  the  thigh  ; and  it  is 
about  three  inches  above  the  condyle  that  the  great  artery 
passes  betwixt  this  tendon  and  the  bone  perforating  the  triceps, 
to  get  from  the  fore  to  the  back  part  of  the  thigh,  and  down 
into  the  ham. 

The  use  of  all  these  muscles  is  entirely  the  same,  making 
allowance  for  their  various  degrees  of  oblique  insertion  ; and 
they  must  be  very  powerful,  by  the  great  distance  of  their 
origins  from  the  centre  of  that  bone  which  they  move,  so  that 
while  other  muscles  pull  in  a direction  very  oblique,  these 
three  heads  of  the  triceps  must  pull  more  at  I’ight  angles,  and 
therefore  at  a more  favourable  direction. 

CLXII.  The  OBTURATOR  EXTERNUs  is  named  after  the  ob- 
turator ligament,  from  which  it  arises.  The  ligament  and  the 
muscles  shutting  up  the  foramen  thyroideurn  are  named  obtu- 
rators, and  it  is  sometimes  named  rotator  femoris  ex- 
TRORSUM,  from  its  turning  the  thigh  outwards.  It  arises  from 
the  ramus  of  the  ischium  and  os  pubis,  where  they  form  the 
margins  of  the  thyroid  hole  ; and  from  the  outer  surface  of  the 
ligament,  which  it  occupies  entirely,  leaving  only  room  for  the 
obturator  vessels  and  nerves.  It  is  a short  muscle  ; its  origin 
is  broad,  and  its  insertion  narrow,  so  that  it  is  of  a conical  form  ; 
for  the  flesh  of  its  muscles  is  gathered  very  soon  into  a round 
short  tendon,  which  twists  under  the  thigh-bone  betwixt  it  and 
the  pelvis ; so  that  it  is  in  a manner  rolled  round  the  thigh- 
bone, being  inserted  into  the  root  of  the  great  trochanter.  It 

you.  I.  H li 


242 


]\IUSCL£S  MOVING  THE  THIGH-BONE. 


pulls  the  thigh  forwards,  but  is  more  peculiarly  a rotator  of 
the  thigh.  This  muscle  is  of  the  second  layer,  and  the  succes- 
sion of  all  the  muscles  is  this  ; the  upper  layer  consists  of  the 
psoas  and  iliacus,  where  they  come  out  from  the  abdomen,  of 
the  pectinalis,  and  of  the  long  head  of  the  triceps;  the  second 
layer  consists  of  the  short  head  of  the  triceps;  and  the  third 
layer  consists  of  ihe  obturator  externus  at  the  upper  part,  and 
the  triceps  magnus,  or  third  head  of  the  triceps,  all  down  to 
the  condyle. 

GlutjEi. — There  are  three  glutaei  muscles,  each  under  the 
other,  and  each  smaller  than  the  muscle  which  covers  it.  The 
FIRST,  arising  from  the  back  part  of  the  ilium,  the  back  of  the 
sacrum,  and  the  sacro-sciatic  ligament,  forms  the  whole  hip,  and 
descends  so  low  as  to  be  inserted  into  one-third  of  the  length 
of  the  linea  aspera,  and  into  the  root  of  the  great  trochanter. 

The  SECOND  arises  from  all  that  portion  of  the  ilium  which 
is  before  this  one,  and  from  the  back  of  the  bone,  and  goes 
down  to  be  inserted  into  the  very  top  of  the  great  trochanter- 

The  THIRD  arises  from  the  back,  of  the  bone  below  the  last ; 
and  it  is  inserted  into  the  root  betwixt  the  apex  of  the  great 
trochanter  and  the  neck  of  the  bone. 

CLXIII.  The  GLUTffius  maximus  arises  from  the  back  of  the 
ilium  nearly  one  half  its  length  ; from  the  joining  of  the  ilium 
and  sacrum  ; from  all  the  spines  and  irregularities  of  the  sa- 
crum; and  from  the  sacro-sciatic  ligament.  Its  thick  fleshy 
fasciculaj  come  in  a winding  and  oblique  direction  down  to  the 
thigh-bone  ; and,  being  gathered  into  a flat  and  pretty  broad 
tendon,  it  is  inserted  into  the  root  of  the  trochanter  major,  and 
down  three  inches  of  the  linea  aspera.  This  is  one  of  the 
largest  and  most  fleshy  muscles  of  the  body ; covers  all  the 
other  muscles  of  the  hip  ; forms  the  contour  of  the  hip  ; pulls 
the  thigh  backwards,  or  the  body  forwards  upon  the  thigh, 
when  the  thigh  is  fixed  : and  being  a wide  spreading  muscle, 
which,  in  a manner,  surroundsits  joint,  its  different  portions  act 
with  different  effects;  not  only  according  to  their  natural  di- 
rection, but  according  to  the  accidental  positions  of  the  pelvis 
with  regard  to  the  thigh-bone. 

CLXIV.  The  glutjEus  medius  or  minor  Is  smaller  than 
the  former,  but  like  it.  It  arises  from  all  the  outside  of  the 
ilium  not  occupied  by  the  glutieus  major.  It,  like  the  other, 
is  a fan-formed  muscle  ; for  its  fibres  converge  from  its  broad 
origin  in  all  the  back  of  the  ilium,  to  form  a short  flat  tendon 
which  is  inserted  into  the  back,  or  into  the  very  top  of  the 
great  trochanter.  It  lies  in  part  under  the  glutieus  maximus ; 
but  its  chief  part  lies  before  the  glutasus  mgximus ; and  as  cer- 
tain portions  of  the  muscle  are  before  the  thigh-bone,  there 


MUSCLES  MOVING  THE  THIGH-BONE.  243 

are  positions  of  the  pelvis  and  thigh-bone  in  which  it  will  pull 
the  thigh  forwards,  although  its  proper  office  is  to  assist  the 
glutfeus  magnus  in  pulling  the  thigh  backwards,  and  moving  it 
outwards  from  the  body. 

CLXV.  The  GLUTa;us  minimus  is  a small  radiated  muscle, 
which  lies  deep,  and  quite  under  the  former.  It  has,  compared 
with  the  former,  a very  narrow  origin;  for  it  arises  chiefly 
from  the  lowest  part  of  the  back  of  the  ilium,  viz.  that  part 
which  forms  the  socket  for  the  thigh-bone,  and  a little  higher 
up,  and  from  the  border  of  the  sciatic  notch.  Its  origin  from 
the  dorsum  ilii  is  bounded  by  a ridge,  which  extends  from  the 
upper  part  of  the  acetabulum  to  the  notch.  It  forms  a short, 
flat,  and  strong  tendon,  which  is  fixed  under  the  root  of  the 
trochanter  major,  betwixt  the  trochanter  and  the  neck  of  the 
bone;  so  that  these  muscles  are  inserted  in  this  succession; 
first,  the  great  glutasus,  below  the  root  of  the  trochanter,  and 
into  the  linea  aspera;  the  middle  gluteus  into  the  back  and 
top  of  the  trochanter;  and  the  smallest  of  the  glutei  is  im- 
planted into  the  roughness  under  the  root  of  the  trochanter. 

Gemini. — The  gemini  are  two  muscles,  or  rather  one  biceps 
muscle ; but  the  heads  are  so  distinct,  that  they  are  reckoned 
two,  and  so  much  alike,  that  they  are  named  gemini. 

CLXVI.  The  uppermost,  the  larger  and  stronger  muscle, 
arises  from  the  spinous  process  of  the  os  ischium. 

CLXVII.  The  second  or  smaller  head  arises  in  like  manner 
from  the  tuber  ischii,  upon  its  ball  or  outer  end.  They  are 
fleshy  in  their  whole  length.  They  meet,  and  unite  their 
tendons  at  the  great  trochanter.  They  are  inserted  firmly 
along  with  the  following  tendon,  at  the  root  of  that  process. 

CLXVIII.  The  pyriformis,  or  pyramidalis,  comes  from 
the  hollow  of  the  sacrum,  runs  in  the  same  line  with  the  lesser 
glutffius,  and  is  inserted  with  the  two  last-named  muscles  in 
the  root  of  the  great  trochanter. 

Its  origin  is  from  the  hollow  of  the  sacrum,  rising  from  the 
vertebras  of  that  bone,  by  three  or  four  small  fleshy  digits ; 
and  from  the  sacro-sciatic  notch,  it  runs  betwixt  the  glutieus 
minor  and  the  gemini,  and  its  round  tendon  is  inserted  betwixt 
them,  somewhat  connected  with  each.* 

The  pyriformis,  gemini,  obturator  internus,  and  quadratus, 
form  what  some  anatomists  have  called  musculi  q,uadri-ge- 
MiNi ; and  they  are  so  much  alike  in  insertion  and  use,  that  it 
would  be  waste  of  time  to  repeat  what  has  been  said  of  the 
gemini  and  obturator. 

This  muscle,  the  pyriformis,  like  the  others,  rolls  the  thigh 
outwards.  Its  name  is  from  its  shape. 

'■  This  miisrle  is  frequently  iivided  by  the  great  sacro  sciatic  nprve. 


244  MUSCLES  MOVING  THE  THIGH-BONE. 

CLXIX.  The  OBTFRATOR  INTERNUS,  ODCe  named  MARSU- 
piALis,  or  uuRBALis,  arises  from  all  the  internal  surface  of  the 
obturator  ligament,  and  from  all  the  edges  of  the  thyroid  hole, 
from  the  ilium,  ischium,  and  pubis.  Its  origin  is  therefore 
circular  and  fleshy.  It  runs  along  the  inside  of  the  os  ischium, 
turns  round  that  bone  betwixt  the  spinous  process  and  the  tu- 
ber. The  hollow  there  is  guarded  with  cartilage,  and  this 
tendon  runs  in  the  hollow,  like  a rope  round  a pulley;  passing 
this,  it  runs  betwixt  the  two  legs  of  the  gemini,  and  its  tendon 
is  united  to  theirs : and  the  three  appearing  almost  like  one 
tendon,  are  inserted  together  into  the  root  of  the  trochanter 
major.  These,  then,  might  with  some  propriety  be  named 
one  muscle;  all  the  three,  viz.  the  two  gemini  muscles,  and 
the  obturator  muscle  passing  between  them,  were  once  ac- 
counted as  one  muscle,  and  then  it  seemed  to  be  a muscle 
with  two  bellies,  and  an  intermediate  tendon ; and  this  inter- 
mediate tendon,  with  two  fleshy  ends,  give  it  the  appearance 
of  a purse,  thence  named  marsupiams,  or  bursalis 

CLXX.  The  ciuadratus  femokis  is  a thin  flat  muscle, 
passing  in  a transverse  direction  betwixt  the  tuber  ischii  and 
the  thigh-bone. 

It  arises  from  the  lower  and  flattened  surface  of  the  tuber 
iscHii  by  a strong  tendinous  beginning.  It  goes  a little 
obliquely  upwards  and  outwards,  and  is  inserted  into  the  back 
of  the  great  trochanter,  in  that  roughness  which  is  found  just 
where  the  trochanter  is  joined  to  the  bone,  and  goes  obliquely 
betwixt  the  trochanter  major  and  the  trochanter  minor. 

It  rolls  the  thigh-bone,  so  as  to  turn  the  toe  outwards,  and 
pulls  it  almost  directly  backwards. 

The  MOTIONS  of  the  thigh  must  be  performed  by  many 
very  strong  muscles,  as  it  moves  under  the  weight  of  the  whole 
body;  and  it  seems  to  be  curiously  contrived,  that  the  muscles 
fit  for  moving  the  thigh  forward,  should  in  certain  positions  of 
the  thigh,  move  it  backwards ; also  giving  an  increase  of 
strength  to  that  motion  of  the  thigh  in  which  most  strength  is 
required. 

There  are  but  fwo  or  chiefly  two  points  for  insertion  ; the 
trochanter  major  and  trochanter  minor.  These  two  points  are 
so  oblique,  that  no  one  muscle,  nor  set  of  muscles,  performs 
any  direct  motions ; for  they  all  twist  round  the  bone’s  axis,  to 
get  at  their  insertion.  The  glutiei,  the  pyriformis,  the  gemini, 
the  quadratus,  the  obturator  internus,  and  obturator  externus, 
all  bend  round  the  axis  of  the  thigh-bone  to  reach  the  tro- 
chanter major.  These  now  may  be  called  the  abductors  of 
the  thigh,  to  pull  it  outwards ; but  we  should  conclude  from 


MUSCLES  MOVING  THE  LEG. 


246 


this  direction,  that  they  could  not  pull  the  thigh  backwards, 
for  the  thigh-bone  would  turn  on  its  axis  and  elude  their  ac- 
tion. 

The  psoas  magnus,  the  iliacus  internus,  the  pectinalis,  and 
the  triceps,  do  in  the  same  manner  go  round  the  inner  side  of 
the  bone : the  two  first  to  be  implanted  into  the  trochanter 
minor,  the  two  latter  into  the  linea  aspera,  just  below  it.  These 
are  justly  named  adductors  of  the  thigh  : their  chief  use  is  to 
draw  the  thighs  together,  and  this  is  their  combined  effect : 
when  the  adductors  act  by  themselves,  they  pull  the  thigh 
forwards,  moving  the  leg,  rolling  the  thigh-bone,  and  turning 
the  toe  out  in  a graceful  step ; which  is  most  peculiarly  the 
effect  of  the  pectoralis  and  triceps.  But  when  we  are  to  finish 
the  motion,  by  pulling  forward  the  body,  which  is  the  same 
with  pulling  back  the  thigh,  it  is  not  merely  the  antagonists 
of  these  muscles,  as  the  glutaei,  the  gemini,  &c.  which  must 
act.  Were  the  glutasi  to  act  alone,  they  would  rather  turn 
the  thigh  upon  its  axis  outwards  than  pull  it  back ; but  the  tri- 
ceps, £c.  act  again  in  conjunction  with  the  glutaei,  &c.  and 
by  the  action  of  the  triceps,  the  inner  trochanter  is  fixed  : the 
further  rolling  of  the  thigh  is  prevented  ; the  full  effect  is  given 
to  the  glutfei  muscles.  When  the  glutrei  act,  they  pull  the 
thigh  directly  backwards,  assisted  by  the  triceps,  pectinalis, 
and  others : for  now  the  thigh-bone  is  so  far  advanced  before 
the  body,  that  those  muscles,  as  the  triceps  which  were  benders 
of  the  thigh  in  its  first  position,  are  extensors  when  it  is  ad- 
vanced a step  before  the  body ; or,  perhaps,  it  will  be  more 
explicit  to  say,  that  when  the  thigh  is  moved  one  step  before 
the  body,  the  iliacus  internus,  psoas  magnus,  and  triceps  mus- 
cles, agree  with  the  glutffii  muscles  in  bringing  the  trunk  for- 
wards to  follow  the  limb,  and  then  in  fixing  and  stiffening  the 
trunk  upon  that  limb,  till  the  other  thigh  is  advanced  again  a 
step  before  the  body.  , 

The  MUSCLES  of  the  leg  are  the  most  simple  of  all ; for  the 
knee  is  a mere  hinge,  at  least,  it  is  so  in  all  our  ordinary  mo- 
tions, so  that  there  is  no  action  to  be  performed,  but  those  of 
mere  flexion  and  extension,  and  there  are  only  two  classes  of 
muscles  to  be  described,  the  extensors  and  the  flexors  of  the 
leg. 

1.  The  EXTENSORS  of  the  leg.  The  only  muscles  which 
extend  the  leg  are  those  four-  which  may  be  very  fairly  reckon- 
ed a quadriceps  extensor  cruris.  Indeed  the  French  anato- 
mists arrange  tiiem  so.  Sabatier  calls  them  the  triceps  femoris. 
These  muscles,  which  all  converge  to  the  patella,  and  are  in- 


246 


MUSCLES  MOVING  THE  LEG. 


serted  in  It,  are,  rectus  femoris, — crur^eus,  or  femorjeus, — 

VASTUS  EXTERNUS, VASTUS  INTERNUS. 

And  these  are  all  implanted  by  one  tendon;  because  the 
joint  being  a hinge,  bending  only  in  one  direction,  its  muscles 
could  have  given  but  one  motion,  however  oblique  their  origin 
and  course  had  been. 

2.  The  FLEXORS  of  the  leg  are  one  on  the  outside,  and  four 
on  the  inside  of  the  leg;  the  tendons  of  the  outside  being  im- 
planted into  the  upper  knob  of  the  fibula,  and  those  in  the  in- 
side into  the  rough  head  of  the  tibia,  forming  the  ham-strings, 
and  extending  their  tendons  or  aponeurotic  expansions  down- 
wards upon  the  leg. 


INSIDE  FLEXORS. 

Sartorius,  Gracilis, 

Semitendinosus,  Semimembranosus. 

OUTSIDE  FLEXOR. 

Biceps. 

EXTENSORS  OF  THE  LEG. 

CLXXI.  The  RECTUS  FEMORIS,  sometimes  rectus  cruris, 
IS  so  named  from  its  direction  ; it  arises  by  two  heads.  The 
first  or  greater  head  arises  from  the  lower  spinous  process  of 
the  ilium  by  a short  round  tendon ; its  second  head  is  in  a dif- 
ferent, and  somewhat  of  a curved  direction  ; for  it  comes  from 
the  edge  of  the  acetabulum,  and  from  the  capsular  ligament. 
These  join  together,  and  form  a flat  tendon  of  four  inches  in 
length,  which  becomes  gradually  fleshy  and  larger  down  to  its 
middle,  and  then  again  contracts  towards  the  patella.  There 
is  a middle  tendinous  line,  running  the  whole  length  of  the 
muscle,  especially  conspicuous  on  its  back  part,  and  towards 
that  central  line  all  the  muscular  fibres  converge. 

The  rectus  is  united  at  the  sides  to  the  vasti,  at  the  back  part 
of  the  crurseus  ; and  its  tendon,  along  with  that  of  the  cruraeus, 
goes  to  be  directly  implanted  into  the  rotula  or  patella. 

The  rectus  cruris  is  the  first  of  those  muscles  which  Sabatier 
calls  the  triceps  femoris  ; they  may  be  more  properly  named 
the  q,uadriceps  cruris. 

This  large  mass  of  muscle  or  flesh  enwraps  the  whole  of  the 
thigh-bone  behind  as  well  as  before;  for,  first,  the  crur^us 


MUSCLES  MOVING  THE  LEG. 


247 


arises  fleshy  from  all  the  forepart  of  the  bone.  The  vastus 
UXTEBNUS  from  the  great  trochanter,  and  all  the  back  part  and 
outer  side  of  the  bone ; and  the  vastus  internus  arises,  in 
like  manner,  from  the  lesser  trochanter,  and  all  the  inner  side 
of  the  bone,  from  the  trochanter  major  all  round  to  the  origin 
of  the  cruraeus. 

CLXXII.  The  crukseus  arises  from  the  forepart  of  the 
femur,  between  the  two  trochanters,  and  it  continues  its  origin 
from  the  forepart  of  the  femur,  the  whole  way  down  to  within 
two  inches,  or  little  more,  of  the  patella.  About  three  inches 
from  its  origin  it  is  joined  by  the  vastus  externus,  which 
unites  with  it  at  the  outer  edge  and  forepart ; and  the  vastus 
iNTERNUs  comes  into  it  about  five  inches  below  its  origin,  and 
it  joins  it  at  the  inner  edge  and  forepart.  At  its  lower  part  it 
is  joined  to  the  tendon  of  the  rectus,  to  form  but  one  large  ten- 
don, which  is  inserted  into  the  rotula.  By  Albinus,  the  plate 
of  this  muscle  is  given  in  union  with  the  two  vasti,  which  is  the 
best  method  of  describing  the  muscle,  as  it  is  very  seldom  to 
be  made  out  distinct  from  these  two  muscles. 

Under  the  cruraeus  are  sometimes  found  two  little  muscles,  or 
rather  two  little  slips  of  this  muscle,  which  are  quite  distinct. 
They  arise  on  the  forepart  of  the  thigh-bone,  two  or  three 
inches  above  the  capsule  of  the  joint;  and  they  are  inserted  into 
the  capsule  on  each  side  of  the  patella,  evidently  for  the  pur- 
pose of  pulling  it  up,  to  prevent  its  being  catched;  and  when 
these  two  (subckuk^j)  are  not  found  as  distinct  muscles,  some 
fibres  of  the  cruraeus  supply  their  place. 

CLXXIII.  The  vastus  externus  is  the  largest  of  these 
three  muscles. 

Its  origin  is,  by  a pretty  thick  and  strong  tendon,  from  the 
lower  and  forepart  of  the  trochanter  major;  and  it  continues 
its  origin  from  the  root  of  the  trochanter  all  down  the  linea  as- 
pera,  to  that  rough  line  which  goes  to  the  outer  tuberosity  of 
the  thigh-bone. 

It  touches  the  end  of  the  cruraeus  about  four  inches  below  its 
origin,  and  continues  attached  to  it  the  whole  way  down  ; and 
then  it  forms  a fiat  tendon  which  connects  itself  with  the  ten- 
don of  the  RECTUS  EEMOKis,  and  then  embraces,  in  a semi- 
circular manner,  the  outside  of  the  patella.  And  several  of 
the  fibres  of  this  aponeurosis  not  only  cross  over  the  rotula,  but 
go  dow'ii  over  its  opposite  side  to  glide  along  the  head  of  the 
tibia,  and  to  be  inserted  into  the  inner  side  of  the  knee. 

CLXXIV.  The  VASTUS  internus  is  neither  so  large  nor  so 
fleshy  as  the  vastus  externus  ; but  it  is  exceedingly  like  it  in 
all  other  respects. 


24a 


MUSCLES  MOVING  THE  LEG. 


Jt  arises  from  the  forepart  of  the  trochanter  minor,  just  un- 
tier  the  insertion  of  the  psoas  magnus;  and  it  continues  its  ori- 
gin from  the  linea  aspera  the  whole  way  down  to  the  inner 
condyle,  exactly  opposite  to  the  origin  of  the  vastus  externus ; 
they  Jeave  just  a channel  betwixt  them.  The  vastus  internus^ 
very  soon  after  its  origin,  joins  itself  to  the  cruraeus,  or  middle 
portion,  and  accompanies  it  in  all  its  length;  and,  at  the  dis- 
tance of  two  inches  from  the  rotula,  it  unites  itself  with  the 
tendon  of  the  cruraiusat  its  internal  edge;  and  this  tendon  com- 
pletes that  junction  which  unites  the  four  muscles  into  a quadri- 
ceps cruris.  This  vastus  internus  descends  much  lower,  in  a 
fleshy  form,  than  the  external  vastus  does,  and  forms  that  fleshy 
cushion  which  covers  the  inner  side  of  the  knee-joint.  Its  ten- 
don embraces  the  rotula,  somewhat  in  the  same  circular  form 
with  the  vastus  externus ; and,  like  the  externus,  it  sends  some 
fibres  across  the  knee-pan,  to  be  inserted  in  the  outer  part  of 
the  head  of  the  tibia. 

The  KECTijs,  and  the  vastus  externus,  jnternus,  and 
CRUR^us,  form  one  large  mass  of  flesh,  which  embraces  and 
encloses  all  the  thigh-bone ; and  they  are  so  connected,  that 
the  cruraeus  cannot  be  separated,  and  cannot  be  neatly  dis- 
tinguished. 

The  use  of  these  four  muscles  is  evident;  to  extend  the 
leg,  and  to  bend  the  thigh  on  the  trunk,  or  reciprocally  to 
bend  the  trunk  on  the  thigh.  This,  or  these  two  motions  al- 
ternately, is  the  common  use  of  these  muscles,  as  in  walking ; 
and  they  are  most  peculiarly  useful  in  running  and  leaping. 

After  describing  a large  mass,  conjoined  in  one  tendon,  and 
concurring  in  one  simple  action,  it  is  superfluous  to  say  that  its 
power  must  be  great.  This  power  must  be  still  farther  in- 
creased by  the  rotula,  which  removes  the  force  from  the 
centre,  and  gives  the  advantage  of  a pulley,  which  it  really 
and  truly  is ; without  this  pulley,  these  muscles  could  be  of 
no  use  in  certain  situations ; for  instance,  in  the  recumbent 
posture  ; for  then  the  extending  muscles,  being  in  the  same 
line  with  their  bones,  could  have  no  further  power ; but  the 
rectus,  by  the  pulley  of  the  rotula,  and  by  its  attachment  to 
the  basin,  raises  the  trunk,  or  at  least  helps  the  psoas,  the 
iliacus,  and  the  muscles  of  the  belly. 

The  rotula  is  again  attached  to  the  tibia  by  a strong  ligament 
to  sustain  the  pulling  of  these  great  muscles.* 

* Theje  muscles  are  in  continual  action  : for  their  office  is  to  resist  the  bending  of  tlie 
knee,  which  would  happen  by  tliis  encumbent  wekht  of  the  body;  so  that  the  continual 
support  of  the  body  depends  wholly  on  these  muscles  ; and  they  are  the  great  agents  in 
running,  leaping,  walking,  &c.  Since  by  extending  the  knee  they  raise  the  weigjit  of  the 
pelvis  and  trunk,  and  of  all  the  body,  they  must  be  very  powerful ; and  accordingly,  when 
they  are  weighed  against  their  antagonist  muscles,  we  find  them  greatly  to  exceed,  for  the 


MUSCLES  MOVING  THE  LEG. 


249 


FLEXORS  OF  THE  LEG. 

CLXXV.  The  sARTORius  or  taylor’s  muscle,  is  so 
named  from  its  bending  the  knees,  and  drawing  the  legs 
across.  It  is  the  longest  muscle,  and  a very  beautiful  one  ; 
extends  obliquely  across  the  whole  length  of  the  thigh,  cros- 
sing it  like  a fillet  or  garter,  about  two  inches  in  breadth. 

It  arises  from  the  upper  spinous  process  of  the  os  ilium,  by 
a tendon  about  half  an  inch  in  length  ; its  thin  flat  belly  ex- 
tends obliquely  across  the  thigh,  like  a strap,  and  is  inserted 
into  the  same  oblique  form  into  the  inner  tubercle  of  the  bead 
of  the  tibia ; its  aponeurosis  spreads  widely,  going  over  the 
whole  joint  of  the  knee,  a thin  sheet  of  tendon. 

From  the  oblique  position  of  the  muscle,  it  might  in  action 
change  its  place  ; but  it  is  so  far  embraced  by  the  fascia  lata, 
and  is  tied  by  such  adhesions,  as  to  form  something  like  a pe- 
culiar sheath  of  itself. 

It  turns  the  thigh  like  the  quadratus  gemini,  and  obturator 
muscles.  It  also  bends  the  leg  upon  the  knee  ; and  when  the 
leg  does  not  yield,  it  bends  the  thigh  upon  the  pubes ; or 
where  the  thigh  is  also  fixed,  it  bends  the  body  forwards ; but 
in  performing  that  action,  whence  it  has  its  name,  it  does  all 
these  ; for  first  the  leg  and  thigh  are  rolled,  then  the  thigh  is 
raised,  then  the  leg  is  bent  to  draw  it  across.  Though  a small 
muscle,  yet  it  is  of  great  power  from  its  origin,  and  in  some 
degree,  its  insertion  also,  being  much  removed  from  the 
centre  of  motion. 

CLXXVI.  The  gracilis,  sometimes  called  rectus  in- 
TERNUs  FEMORis,*  is  a Small,  flat,  thin  muscle,  in  its  general 
shape  somewhat  like  the  sartorius. 

It  arises  by  a flat  tendon  of  two  Inches  in  length  from  the 
ramus  of  the  os  pubis,  and  near  the  symphysis  ; and  it  passes 
immediately  under  the  integuments  down  to  the  knee ; it  passes 
by  the  inner  condyle  of  the  knee,  in  the  form  of  a short 
round  tendon,  and,  as  it  bends  behind  the  head  of  the  tibia, 
it  is  bound  down  by  a bundle  of  tendinous  fibres,  which, 
crossing  it,  go  the  back  part  of  the  leg.  After  passing  the 
head  of  the  tibia,  it  turns  obliquely  forwards  and  downwards  ; 
it  here  runs  behind  the  tendon  of  the  sartorius,  and  before 
that  of  the  semitendinosus.  It  is  inserted  with  the  sartorius 
into  the  side  of  the  tuberosity,  at  the  top  of  the  tibia. 

etiADRicEPS.  (i.  e.)  the  rectus,  crurseus,  and  vast!,  will  weigh  four  pounds,  while  the  biceps 
&c.  tlieir  antagonists,  weigli  but  two  pounds.  This  experiment  was  often  repeated  by  the 
great  Cowper,  for  Mr  Brown,  who  was  delivering  lectures  on  muscular  motion. 

* Gracius,  is  from  its  smallness ; rectos  interxus,  is  from  it?  straight  direction. 

VOL.  I.  h i 


250 


MUSCLES  MOVING  THE  LEG. 


This  muscle  runs  also  in  a line  so  wide  from  the  centre  of  ^ I 
motion,  that  its  power  is  very  great.  It  serves  chiefly  as  a ' 
flexor  of  the  leg  : when  the  leg  is  fixed,  it  must  by  its  origin 
from  the  pubes  be  a flexor  of  the  thigh,  and  an  adductor  in 
nearly  the  same  direction  with  the  pectineus  and  triceps;  and  ■ 
it  is  worth  observing,  that  while  the  knee  is  straight,  the  sar- 
torius  and  the  gracilis  cannot  bend  the  knee  ; they,  on  the 
contrary,  keep  it  steady  and  firm  ; but  when  the  knee  is  bent, 
they  come  into  action  ; for  in  proportion  as  the  muscles  which 
have  made  the  flexion  are  contracted,  they  are  less  able  to 
contract  farther,  and  therefore  it  is  desirable,  that  more 
muscles  should  come  into  play. 

CLXXVII.  The  semitendinosus  is  so  named  from  its 
lower  half  being  composed  of  a small  round  tendon ; and  a&  ^ 
tendon  was  once  misnamed  nerve,  this  is  the  seminervosus 
of  Winslow,  Douglas,  and  others. 

Its  origin  is  from  the  tuberosity  of  the  ischium  (along  with 
the  semimembranosus  and  touching  the  biceps,)  by  a short 
thick  tendon.  It  also  arises  by  many  oblique  fasciculi  of 
fibres,  from  the  posterior  portion  of  its  opposite  muscle  the 
biceps  cruris.  This  cross  connection  betwixt  the  two  muscles 
continues  for  three  inches  down  from  the  tuber  ischii ; it  then 
departs  from  the  biceps,  goes  obliquely  inwards,  and  is 
flattened  and  contracted  into  a tendon,  six  inches  from  the 
knee,  and  getting  round  the  he?id  of  the  tibia,  it  comes  for- 
ward to  be  inserted  into  the  tuber,  at  the  head  of  that  bone. 

At  this  place,  the  tendon  grows  broad  and  flat ; it  is  expanded 
and  as  it  were  grasps  the  inner  side  of  the  knee  ; its  upper 
edge  is  joined  to  the  lower  edge  of  the  tendon  of  the  gracilis, 
so  that  the  sartorius,  gracilis,  and  semitendinosus  are  im-  : 
planted  like  one  muscle  ; and  this  tendinous  expansion  seems 
like  a capsule,  for  enclosing  the  heads  of  the  tibia  and  femur, 
and  for  strengthening  the  knee-joint.  The  semitendinosus 
bends  the  leg.  I 

CLXXVni.  The  semimembranosus  has  its  name  from  the 
muscle,  which  is  flat,  thick,  and  fleshy,  beginning  and  ending  [ 
with  a flattened  tendon,  somewhat  like  a membrane,  but  infi- 
nitely thicker  and  massier  than  such  name  should  imply. 

It  arises  from  the  tuber  ischii,  before  the  semitendinosus 
and  biceps.  It  arises  a broad,  thin,  and  flat  tendon,  of  about 
three  inches  in  length.  It  becomes  fleshy  and  thick  in  its 
middle,  but  it  soon  becomes  thinner  again,  and  terminates  in  | 
a short  tendon,  which,  gliding  behind  the  head  of  the  tibia, 
is  inserted  there.* 

* The  tn  o tendons  of  this  muscle,  the  membranous  tendon  at  the  liead,  and  this  smaller 
one  by  which  it  is  inserted,  stand  so  obliquely,  that  the  muscular  fibres  betwixt  them  must 


MUSCLES  MOVING  THE  LEG. 


251 


This  muscle  has  little  connection  with  any  other.  It  lies 
i ttnder,  or  more  particularly  speaking,  on  the  inside  of  the  se- 
I mitendinosus,  and  the  two  together  form  the  inner  ham-strings. 
' The  ham-string  muscles  contribute  also  to  another  motion. 

Though  when  extended  the  tibia  cannot  roll,  yet  when  we  sit 
: with  our  knees  bent,  it  can  roll  slightly ; and  such  rolling  is 

accomplished  by  these  muscles.  All  these  muscles  which 
bend  the  leg,  and  which  consequently  extend  the  thigh  at  the 
same  time,  are  muscles  of  great  power,  because  they  arise 
in  one  common  point,  the  tuber  ischii,  and  that  point  is  veiy 
far  distant  from  the  centre  of  motion. 

There  is  still  one  small  muscle,  a flexor  of  the  leg,  which 
performs  this  rotation  during  the  bent  state  of  the  knee,  with 
most  particular  power. 

CLXXIX.  The  musculus  poplit^us,  Avhich  is  so  named 
from  its  lying  in  the  ham,  is  a small  triangular  muscle,  lying 
across  the  back  part  of  the  knee-joint,  very  deep  under  the 
ham-strings,  and  under  the  muscles  of  the  leg. 

Its  origin  is  from  the  outer  condyle  of  the  thigh-bone,  and 
from  the  back  part  of  the  capsule  of  the  joint.  Its  tendon  is 
short  and  thick,  but  of  no  great  extent.  It  passes  fleshy  behind 
the  knee-joint ; and  it  is  inserted  broad  into  a ridge  on  the 
back  part  of  the  tibia;  so  that  by  .its  small  origin  and  broad 
insertion,  it  is  a fan-like  muscle,  its  upper  fibres  being  almost 
transverse,  and  its  lower  fibres  nearly  perpendicular.  Besides 
bending  the  leg,  it  is  useful  by  pulling  aside  the  capsule  to 
prevent  its  being  caught.  ^ 

CLXXX.  The  biceps  cruris,  so  named  from  having  two 
heads,  a long  and  short  one,  lies  immediately  under  the  skin, 
in  the  back  part  of  the  leg,  running  down  from  the  pelvis  to 
the  knee,  to  form  the  outer  ham-string. 

It  is  the  single  flexor  on  the  outside  of  the  thigh.  Its  origin 
is  from  the  outer  part  of  the  tuber  ischii,  by  a tendon  of  an 
inch  and  a half  in  length.  And  this  tendon  is,  in  its  origin, 
closely  united  with  that  of  the  semitendinosus  for  two  inches,or 
at  least  the  whole  length  of  the  tendon.  After  a short,  but  very 
thick  fleshy  belly,  it  degenerates  into  a tendon,  especially  on 
its  back  part;  and  this  tendon,  which  begins  above  the  middle 
of  the  thigh,  is  continued  the  whole  way  down. 

About  one- third  down  the  bone  is  the  beginning  of  the 
second,  or  short  head,  which  has  its  origin  all  the  way  down 
the  linea  aspera,  to  the  line  above  the  outer  condyle  of  the 
thigh-bone ; and  here  it  is  somewhat  connected  with  the  origin 
of  the  vastus  externus  muscle,  and  the  insertion  of  the  glutseus 

be  very  oblique ; for  the  membranous  tendon  descends  low  upon  the  back  part  or  edge,  and 
?he  tendon  of  insertion  begins  high  upon  the  fore  edge  of  the  muscle. 


252 


MUSCLES  MOVING  THE  LEG. 


inagnus.  The  tendons  of  the  two  heads  are  joined  a little 
above  the  inner  condyle,  and  go  outwards  to  be  inserted  into 
the  outer  part  of  the  head  of  the  fibula,  forming  the  outer  ham- 
string. 

Its  insertion  surrounds  the  head  of  the  fibula,  and  a small 
portion  also  sinks  betwixt  the  bump  of  the  fibula  and  the  inner 
head  of  the  tibia,  to  be  implanted  into  it  also. 

This  muscle,  like  the  opposite  ones,  serves  for  bending  the 
leg.  The  short  head  simply  bends  the  leg.  The  long  head 
assists  the  short  one  in  bending  the  leg,  and  is  also  a muscle 
of  the  thigh. 

The  muscles  of  the  foot  are  six  extensor  and  two  flexor 

MUSCLES. 


EXTENSORS. 


Gastrocnemius  vel  gemellus, 

Pt  .ANTARIS, 

Gastrocnemius  internus  vel  soleus. 
Tibialis  posticus, 

Peroneus  longus,  ) . , » , , 

^ > on  the  outside  of  the  leg. 


lying  on  the  back 
part  of  the  leg. 


— BREVIS, 


The  plexors  are, 

The  tibialis  anticus,  ) , . ^ , 

TLo  > lying  on  the  forepart  of  the  leg. 

Ihe  PERONEUS  TERTIUS,  S ® ^ ° 


CLXXXI.  The  gastrocnemius  is  often  divided  into  three 
muscles,  named  gastrocnemii  or  gemelli.  But,  far  from 
counting  thus,  we  should  rather  favour  the  arrangement  of 
Douglas,  who  couples  this  with  the  next  muscle,  as  forming  a 
quadriceps,  or  two  muscles  joined  with  two  heads  each,  and 
he  calls  it  the  extensor  suralis. 

The  gastrocnemius  is  the  great  muscle  of  the  calf  of  the 
leg,  its  two  heads  are  two  very  large  and  fleshy  bellies,  which 
arise  from  the  tubercles  of  the  thigh-bone.  The  inner  head 
is  the  larger,  and  arises  b)"  a strong  tendon  from  the  back  of 
the  inner  condyle,  and  a little  way  up  the  rough  line;  and  it 
has  also  a strong  adhesion  to  the  capsular  ligament  of  the 
knee. 

The  outer  head  is  shorter  than  this  : it  arises  in  the  same 
way,  from  the  outer  tubercle  of  the  thigh-bone ; and  the  two 
muscles  meet  and  run  down  together,  forming  the  appearance 
of  a rapha,  by  the  direction  of  their  fibres  ; but  the  two  bellies 
continue  distinct  till  they  meet  in  the  middle  of  the  leg.  They 
are  distinct  at  their  back  part;  but,  at  their  forepart,  they 


MUSCLES  MOVING  THE  LEG. 


253 


are  connected  by  a tendinous  aponeurosis,  or  strong  but  flat 
tendon ; and  the  two  bellies  being  about  the  middle  of  the  leg, 
united  firmly,  they  form  a large  flat  tendon,  very  broad  at  its 
beginning,  which  unites  with  that  of  the  soleus  a little  above 
the  ankle. 

CLXXXIL  Soleus. — This  name  is  from  its  resemblance 
to  the  soal  fish  ; and  it  is  often  named  gastrocnemius  inter- 
Nus  This,  like  the  last  muscle,  has  two  heads,  which  arise 
from  either  bone. 

One  head  arises  from  the  head  of  the  fibula,  and  continues 
to  adhere  to  one-third  of  the  upper  part  of  the  bone  ; another 
head  arises  from  about  three  inches  of  the  part  of  the  tibia, 
immediately  below  the  insertion  of  the  popliteus.  The  first 
of  these  heads  is  large  and  round ; the  second  is  smaller  and 
round;  they  unite  immediately;  and  a large  fleshy  belly  is 
formed,  with  still  a conspicuous  division  betwixt  the  flesh  of 
the  two  heads.  The  great  tendon  begins  about  half-way  down 
the  leg,  but  still  is  intermixed  with  fleshy  fibres  till  it  approach 
the  heel.  A little  below  the  middle  of  the  leg,  this  tendon  is 
united  with  the  tendon  of  the  gastrocnemius,  to  form  the  great 
back  tendon,  named  tendo  Achillis ; and  sometimes,  though 
very  rarely,  chorda  magna. 

The  tendon  is  large ; it  grows  smaller  as  it  approaches  the 
heel ; when  it  touches  the  extremity  of  the  heel-bone,  it  ex- 
pands to  take  a firmer  hold. 

In  running,  walking,  leaping,  &ic.  this  muscle,  with  the 
extensors  of  the  leg,  are  the  principal  agents.  The  ex- 
ternal gastrocnemius  has  double  power ; for,  arising  from  the 
tubercles  of  the  thigh-bone,  it  is  both  an  extensor  of  the 
foot  and  a flexor  of  the  leg ; but  the  gastrocnemius  internus  is 
a mere  extensor  of  the  foot,  and  both  together  have  such 
strength  as  often  to  break  the  tendo  Achillis. 

CLXXXIIl.  Plantaris. — This  muscle  is  named  from  a 
mistaken  notion  of  its  going  to  the  planta  pedis,  or  sole  of  the 
foot,  to  form  the  plantar  aponeurosis,  like  the  palmaris  of  the 
hand  : but.  in  fact,  it  does  not  go  to  the  sole,  but  is  a mere 
extensor  of  the  foot,  inserted  along  with  the  tendo  Achillis. 

This  long  and  slender  muscle  is  situated  under  the  gastroc- 
nemius externus.  It  arises  from  the  external  condyle  of  the 
femur,  wholly  fleshy  ; it  also  has  an  attachment  to  the  capsular 
ligament  of  the  joint ; after  an  oblique  fleshy  belly,  of  about 
three  inches,  it  forms  its  small  flat  tendon.  The  tendon  runs 
beUvixt  the  inner  head  of  the  gastrocnemius  and  the  soleeus  ; 
and  when  the  tendo  Achillis  begins,  the  tendon  of  the  plantaris 
attaches  itself  to  the  inner  edge,  and  forepart  of  the  Achillis 
tendon ; it  accompanies  it  down  to  the  heel,  running  in  a 


2154 


MUSCLES  MOVING  THE  LEG. 


groove  which  seems  made  to  receive  it ; and  it  is  implanted 
with  the  tendo  Achillis,  into  the  inner  side  of  the  heel-bone. 
It  is  often  wanting. 

The  use  of  this  muscle  is  to  tuck  up  the  capsule,  in  the  great 
bendings  of  the  knee  joint,  and  to  assist  the  gastrocnemii  mus- 
cles. 

The  PERON^i  muscles  are  those  which  arise  from  the  fibula. 
They  are  named  from  their  length  being  different;  the  pero- 
N.^;us  longus  being  as  long  again  as  the  brevis,  for  it  is  one- 
half  longer  in  its  origin,  the  one  rising  at  the  head,  the  other 
at  the  middle  of  the  bone  ; and  again,  it  is  one-half  longer  at 
its  insertion,  going  fully  round  under  the  foot  to  the  opposite 
side,  while  the  shorter  peronteus  stops  at  the  side  of  the  foot 
to  be  inserted. 

CLXXXIV.  The  peron^eus  longus  is  so  named  from  its 
lying  along  the  fibula.  It  arises  partly  tendinous,  chiefly 
fleshy,  from  the  upper  knob  of  the  fibula,  and  from  the  ridge 
of  the  bone  down  to  within  three  inches  of  the  ankle.  It  has 
another  small  slip  of  a head  from  the  upper  part  of  the  tibia, 
above  where  the  fibula  joins  ; it  has  also  adhesions  to  the  ten- 
dinous partition,  which  separates  this  from  the  extensor  digi- 
TORUM  COMMUNIS  and  the  soleus. 

Its  tendon  begins  very  high,  above  the  middle  of  the  leg, 
and  it  continues  to  receive  the  fleshy  fibres,  almost  at  right 
angles  in  the  penniform  manner.  The  tendon  is  concealed 
down  to  about  or  below  the  middle  of  the  leg.  Then  it  is 
seen  immediately  under  the  integuments,  and  we  can  easily 
distinguish  it  through  the  skin,  being  that  acute  line  or  string, 
which  runs  down  behind  the  outer  ankle,  and  which  gives  shape 
to  that  part. 

i In  passing  the  outer  ankle  it  runs  down  through  a cartilagi- 
nous pulley,  or  annular  ligament,  which  also  transmits  the  pero- 
nKus  brevis : it  leaves  the  peronteus  brevis  on  the  side  of  the 
foot ; and  passing  by  itself  in  a groove  of  the  heel-bone  it 
bends  obliquely  across  the  arch  of  the  foot,  goes  quite  down 
to  the  opposite  side,  and  is  inserted  into  the  metatarsal  hone 
of  the  great  toe,  and  the  great  cuneiforme  hone  on  which  it  is 
founded.  Under  the  eminence  of  the  os  cuboides,  it  sufiers 
great  friction,  so  as  to  be  thickened  to  a degree  of  ossification, 
and  to  resemble  a sesamoid  bone.  It  is  also  thickened  in  a 
lesser  degree,  as  it  passes  the  outer  ankle  ; and  in  all  this  length, 
it  is  tied  down  by  a strong  ligamentous  expansion. 

It  is  a powerful  extensor  of  the  leg ; it  also  gives  that  obli- 
quity to  the  foot,  which  is  .so  handsome  and  natural,  and  use- 
ful in  walking.  This  muscle  particularly  turns  down  to  the 
ground,  the  inner  edge  of  the  foot  j so  it  presses  to  the  ground 


MUSCLES  M0VIN6  THE  LEG. 


256 


tbe  ball  of  the  great  toe,  and  that  is  the  part  which  touches  the 
ground,  and  which  feels  sore  after  long  walking,  or  violent 
leaping  or  running  : It  is  by  that  part  we  push,  in  making  a 
step  ; so  that  this  muscle  is  perceived  to  be  continually  active 
in  all  motions  of  walking,  leaping,  running,  and  more  particu- 
larly in  dancing. 

CLXXXV.  The  peron^us  brevis  is  like  its  fellow  except 
in  length  and  insertion.  Its  origin  is  from  the  ridge  of  the 
fibula,  beginning  about  one-third  down  the  bone,  and  continu- 
ing its  adhesion  the  whole  way  to  the  ankle.  It  also  has  adhe- 
sions to  the  tendinous  partition  which  is  betwixt  it,  and  the 
common  extensor;  so  that  these  two  muscles  are,  by  such  ad- 
hesions, very  difficult  to  dissect.  It  is  smaller  at  its  origin,  but 
increases  in  its  fleshy  belly  as  it  descends ; and  it  is  fleshy 
low'er  down  than  the  peronteus  longus.  It  is,  like  it,  a penni- 
Ibrm  muscle.  The  tendons  of  the  two  peronaei  pass  together, 
by  the  outer  ankle,  in  the  same  ring  ; but  the  tendons  cross 
each,  other ; for  the  peron^us  longus  is  in  its  belly  more  for- 
ward. The  brevis  lies  under  and  behind  it,  quite  covered  by 
it,  and  yet  tbe  tendon  of  the  brevis,  by  creeping  under  the  lon- 
gus, gets  before  it,  just  under  the  outer  ankle  : and  from  that  it- 
runs  in  a separate  groove,  superficially  upon  tbe  outer  edge  of 
the  foot,  to  be  inserted  into  the  metatarsal  bone  of  the  little 
toe.  In  both  muscles  the  tendon  is  upon  the  outer  edge,  and 
begins  almost  as  high  as  the  upper  head  of  each  muscle.  This 
tendon  of  the  peronaeus  brevis,  the  shorter  one,  is  small  where 
it  passes  through  the  pulley,  and  expands  w'hen  it  reaches  its 
insertion,  that  it  may  grasp  the  metatarsal  bone  firmly.  The 
tendon  of  the  longer  muscle  also  expands  a little,  and  some- 
what in  the  form  of  a hand  and  fingers,  taking  hold  of  two 
bones  by  three  little  heads. 

This  muscle  assists  the  former  in  extending  the  foot,  and  co- 
incides well  in  its  oblique  action  with  the  last ; for,  as  the  last 
turned  down  the  inner  edge  of  the  foot,  this  turns  the  outer 
edge  upwards,  which  is  exactly  the  same  motion. 

CLXXXVI.  The  peronaeus  terxius  is  a third  muscle, 
having  its  origin  from  the  fibula  ; but  as  its  tendon  passes  be- 
fore the  maleolus  externus,  and  as  it  is  inserted  into  the  outside 
of  the  foot,  it  has  a contrary  action  to  tbe  peronaeus  longus  and 
peromeus  brevis.  The  peromeus  tertius  lies  on  the  forepart  of 
the  fibula,  and  rises  from  the  middle  of  that  bone,  and  down  to 
near  its  lower  head.  Its  tendon  does  not  pass  into  tbe  same 
sheath  wdth  the  peronEeus  longus  and  brevis,  but  goes  under  the 
annular  ligament  on  the  forepart  of  the  ankle-joint  to  be  inser- 
ted into  the  root  of  the  metatarsal  bone,  which  sustains  the 
little  toe.  It  is  so  much  connected  with  the  extensor  commu- 


'256  MUSCLES  MOVING  ’I'Hfi  LEG. 

nis  digitorum,  that  there  is  often  great  difficulty  in  dividing  the 
two.  The  action  of  this  muscle  balances  the  connection  of 
the  tibialis  anticus,  and  the  two  together  bend  the  foot,  that  is, 
bring  it  to  an  angle  with  the  leg. 

CLXXXVII.  The  tibialis  posticus  is  a penniform  mus- 
cle ; its  tendon  goes  round  the  cartilaginous  pulley  of  the  inner 
ankle. 

It  is  named  tibialis  from  its  origin,  and  posticus  from  its 
place. 

It  arises  from  the  back  part  and  ridge  of  the  tibia,  from  the 
opposite  part  of  the  fibula,  and  from  the  interosseous  membrane 
below  these.  Some  fibres  pass  between  the  bones  at  the  up- 
per part,  and  take  an  origin  from  the  forepart  of  the  tibia ; and 
it  continues  its  attachment  to  the  interosseous  ligament,  quite 
down  to  the  ankle.  It  has  also  strong  attachments  to  the  sur- 
rounding tendinous  partitions.  Its  fibres  are  all  oblique  and 
go  to  the  middle  tendon,  which  is  in  the  heart  of  the  muscle. 
About  the  middle  of  the  tibia,  this  tendon  begins  to  emerge 
from  the  fleshy  belly  ; it  grows  gradually  smaller,  but  still  con- 
tinues to  receive  flesb  quite  down  to  the  ankle.  It  passes  in 
the  groove  of  the  inner  ankle,  and  is  retained  there  by  such  a 
ligament  as  holds  the  peronasi.  After  passing  the  ligament,  it 
expands  in  the  hand-like  form,  to  grasp  the  bones  of  the  tarsus ; 
and  it  is  expanded  much  more  than  the  peronaeus,  for  it  sends 
roots  down  among  the  bones  both  of  the  tarsus  and  metatarsus, 
so  as  to  take  hold  first  on  the  lower  rough  part  of  the  naviculare 
in  passing  over  it.  Then  it  is  implanted  into  the  two  first  me- 
tatarsal bones,  then  into  the  calcaneum,  and  lastly  into  the  os 
cuboides ; and  where  it  passes  over  the  os  naviculare,  it  is 
hardened  into  a sort  of  sesamoid  bone.  In  short,  it  is  im- 
planted in  the  sole  of  the  foot  by  a tendon  like  a hand,  which 
sends  down  its  fingers  among  the  tarsal  and  metatarsal  bones, 
to  take  the  surest  hold.  This  muscle  pulls  the  foot  in,  so  as  to 
put  the  toes  together,  and,  when  balanced  by  the  peronsei,  it 
directly  extends  the  foot. 

CLXXXVIII.  The  tibialis  anticus  crosses  obliquely  the 
forepart  of  the  leg.  It  arises  from  the  forepart  and  outside  of 
the  tibia,  part  of  the  fibula,  and  interosseous  ligament.  It  be- 
gins just  under  the  outer  tuber,  and  continues  its  adhesion  down 
two-thirds  of  the  bone ; then  the  tendon  begins  to  be  formed  : 
and  this  muscle,  like  almost  all  the  smaller  ones  of  the  leg,  ad- 
heres to  the  tendinous  partitions,  and  to  the  fascia,  with  which 
they  are  covered.  The  tendon  begins  almost  with  the  origin 
of  the  muscle,  but  continues  covered  by  the  flesb,  and  not  ap- 
pearing till  within  four  inches  or  so  of  the  ankle,  when  it  begins 
to  pass  obliquely  over  the  leg,  and  having  completed  the  cross- 


MUSCLES  MOVING  THE  TOES. 


257 


ing  above  the  ancle,  it  goes  under  the  annular  ligament  in  a 
peculiar  ring,  it  runs  along  the  side  of  the  foot,  and  is  implanted 
into  the  os  cuneiforme  internum,  and  a small  production  of  the 
tendon  goes  forward  to  be  inserted  into  the  metatarsal  bone  of 
the  great  toe. 

This  muscle  turns  the  great  toe  towards  the  leg,  and 
when  assisted  by  the  peronasus  tertius  directly  bends  the 
foot. 


MUSCLES  OF  THE  TOES. 

The  long  muscles  of  the  toes  are  just  four,  two  flexors, 
and  two  extensor  muscles.  The  flexor  muscles  lie  upon 
the  tibialis  posticus,  or  behind,  betwixt  it  and  the  soliEus.  The 
extensor  muscles  again  lie  under  the  tibialis  anticus,  or  at  least 
their  heads  are  under  it,  and  their  bellies  only  appear  from 
under  it,  about  the  middle  of  the  leg. 

The  flexor  tendons  follow  the  tendon  of  the  tibialis  posti- 
ticuS,  over  the  pulley  of  the  inner  ankle  into  the  hollow  of  the 
foot.  The  tendons  of  the  extensor  muscles  keep  with  that  of 
the  tibialis  anticus,  and  cross  over  the  forepart,  or  raising  of 
the  ankle,  where  the  tibia  is  united  with  the  astragalus.  And 
in  dissection,  we  must  follow  these  in  an  opposite  order  to 
that  in  which  they  are  described,  for  next  to  the  forepart  of  the 
solasus  is,  1st,  the  flexor  pollicis  ; 2dly,  the  flexor  oigi- 
TORUM  ; and  3dly,  the  tibialis  posticus. 

CLXXXIX.  The  flexor  longus  pollicis  is  small  and 
pointed  at  its  origin,  and  arises  fleshy  from  three-fourths  of 
the  fibula,  to  within  an  inch  of  the  outer  ankle,  and  interosse- 
ous ligament.  It  grows  thicker  and  larger  as  it  descends,  and 
adheres  to  the  tendinous  partitions  of  the  tibialis  posticus,  and 
of  the  peroniui.  Its  tendon  can  be  seen  only  about  an  inch 
above  the  joint  of  the  ankle.  It  passes  down  behind  the  inner 
ankle,  where  it  is  bound  in  a sort  of  annular  ligament.  It  there 
passes  under  the  heel-bone,  in  the  arch  of  the  foot,  betwixt 
the  bones  and  the  abductor  pollicis ; it  then  glides  into  the 
channel  made  by  the  two  heads  of  the  flexor  pollicis  brevis; 
it  then  passes  betwixt  the  two  sesamoid  bones  at  the  root  of 
the  great  toe  ; it  then  goes  forward  in  a sheath,  to  be  inserted 
into  the  last  bone  of  the  great  toe,  at  which  implantation  it  is 
enlarged. 

Its  office  is  to  bend  the  great  toe ; but  it  is  also  continually 
useful  at  every  step  in  extending  the  foot,  or  in  keeping  the 
toe  firm  to  the  ground,  while  the  gastrocnemii  raise  the  heel ; 

VOL.  I.  " K k 


268 


MUSCLES  MOVING  THE  TOES. 


and  therefore  we  should  not  be  rash  in  cutting  away  the  great 
toe,  for  in  it  consists  not  the  strength  of  the  foot  only,  but  of 
the  leg. 

CXC.  The  FLEXOii  longus  digitorum  pedis  is  named  in 
addition  the  pehforans,  because,  like  the  perforans  of  the 
hand,  it  runs  its  tendons  through  the  split  tendon  of  a smaller 
muscle,  which  is  lodged  in  the  sole  of  the  foot.  It  is  named 
also  FLEXOR  COMMUNIS,  although  there  be  less  reason  here, 
where  there  are  no  flexors  for  the  individual  toes,  than  in  the 
hand,  where  there  are  separate  flexors  for  the  individual  fin- 

It  arises  from  the  back  and  inner  part  of  the  tibia,  its  whole 
length,  that  is,  from  the  end  of  the  popliUcal  muscle,  and  from 
the  septum  tendinosum,  by  which  it  is  divided  from  the 
tibialis  anticus,  which  lies  immediately  before  it ; and  it  con- 
tinues this  origin  from  the  tibia  down  to  within  three  inches 
or  so  of  the  ankle.  About  the  middle  of  the  muscle  we  find 
fibres  coming  across  to  join  it  from  the  outer  edge  of  the 
tibia,  and  between  these  two  sets  of  fibres  the  tibialis  posticus 
passes.  Its  origin  is  not  easily  separated  before  from'  the 
tibialis  posticus,  nor  behind  from  the  flexor  pollicis. 

The  tendon  is  not  formed  till  near  the  ankle,  (within  two 
inches  of  it,)  and  the  flesh  still  accompanies  it  quite  down  to 
the  joint.  It  crosses  the  tendon  of  the  tibialis  posticus  behind 
the  ankle-joint,  and  goes  forward  in  the  groove  of  the  os  cal- 
cis,  tied  down  by  a sort  of  capsule,  or  annular  ligament.  In 
the  arch  of  the  foot,  it  crosses  the  tendon  of  the  flexor  pollicis, 
from  which  it  receives  a slip  of  tendon ; and  thus  the  office  of 
either  is  assisted  by  the  other,  and  could  he  wholly  supplied 
by  it ; it  then  passes  over  to  the  middle  of  the  sole,  and  grow- 
ing flatter  and  thickei’,  divides  into  four  flat  tendons.  These  go 
forward,  diverging  till  they  arrive  at  the  ends  of  their  metatar- 
sal bones;  then  they  emerge  from  the  aponeurosis  plantaris, 
along  with  the  common  short  flexor.  Now  both  these  tendons 
run  under  a ligamentous  sheath,  and  are  included  in  it  under 
the  first  and  second  bones  of  the  toes ; and  having  perforated 
the  short  flexor  opposite  to  the  second  joint,  they  are  finally 
inserted  into  the  root  of  the  third  or  last  bone  of  each  toe. 
These  tendons,  like  the  corresponding  ones  of  the  hand,  seem 
to  be  split  with  a sort  of  longitudinal  fissure. 

The  proper  use  of  this  muscle  is  to  bend  the  four  lesser 
toes,  to  bend  all  their  joints,  but  more  peculiarly  the  last  bone ; 
and  also  to  extend  the  foot,  keeping  the  point  of  the  toes  to 
the  ground,  consequently  assisting,  the  gastrocnemii,  and  all 
the  muscles  used  in  walking,  &c. 


MUSCLES  MOVING  THE  TOES. 


259 


CXCl.  The  MASSA  CARNEA  JaCOBI  SvLVII,  OF  PLANTS 
PEDIS,  flexor  accessorius,  lies  in  the  sole  of  the  foot;  it  is  a 
small  body  of  flesh,  naturally  connected  with  the  flexor  longus. 
The  massa  carnea  arises  from  the  lower  part  of  the  heel-bone, 
in  two  divisions,  one  (the  external  one)  tendinous,  the  other 
fleshy.  It  is,  upon  the  whole,  pretty  nearly  of  a square  form  ; 
it  joins  the  tendon  of  the  flexor  longus,  before  its  division  into 
tendons  for  each  toe,  and  by  the  advantage  with  which  it  acts 
in  consequence  of  its  origin  from  the  heel -bone,  it  must  be  of 
great  assistance  to  the  flexor.  It  is  more  generally  considered 
in  the  light  of  a supplementary  muscle ; by  some,  it  is  con- 
sidered as  a distinct  muscle,  and  by  others,  as  the  origin  and 
first  beginning  of  the  lumbricales  pedis. 

Thus  Cowper  considers  the  massa  carnea,  and  the  lumbri- 
cales, as  one  and  the  same : that  the  massa  carnea  joins  the 
tendon,  covers  it  with  its  flesh,  continues  fleshy  along  the  com- 
mon tendon,  till  at  the  bifurcation  it  also  parts  along  with  the 
four  tendons,  into  four  small  fleshy  muscles,  which  are  called 
lumbricales. 

Albinus,  again,  paints  the  massa  carnea  distinctly,  termina- 
ting at  the  common  tendon,  and  the  lumbricales  as  arising  dis- 
tinct from  each  of  the  divided  tendons. 

CXCII.  The  FLEXOR  BREVIS  Di oiTOBUM  is  also  named  the 
flexor  sublirais  or  perforatus.  It  arises  from  the  lower  part  of 
the  heel-bone,  or  the  bump  upon  which  we  stand.  It  arises 
by  very  short  tendinous  fibres,  and  being  placed  immediately 
under  the  plantar  aponeurosis,  it  takes  hold  of  it,  and  also  of 
the  tendinous  partitions  betwixt  it,  and  the  two  abductors  of  the 
small  and  of  the  great  toe,  which  are  on  either  side  of  it. 
Under  the  metatarsal  bones,  it  divides  itself  into  four  heads; 
their  tendons  begin  earlier  upon  the  side  next  the  foot ; they 
grow  round,  emerge  from  betwixt  the  dentations  of  the  plantar- 
aponeurosis;  they  then  pass  into  the  vagina,  or  sheath  of 
each  toe ; and  on  this,  the  first  phalanx,  they  lie  over  the  ten- 
dons of  the  long  extensors.  About  the  root  of  the  first  bone, 
they  divide  into  two  little  bands,  wfliich  form  a split  (like 
the  perforatus  of  the  fingers)  for  the  passage  of  the  long 
temlon. 

The  long  tendon  passes  through  it  upon  the  second  joint  of 
the  toe,  and  immediately  after  the  perforated  tendon  fixes  it- 
self by  the  two  forks  to  each  side  of  the  second  bone,  or 
phalanx  of  the  toe. 

Its  use  is  to  bend  the  first  and  second  joints  of  the  toes,  but 
most  peculiarly  the  second.  The  obliquity  of  the  long  flexor 
is  exactly  balanced  by  a corresponding  obliquity  of  the  short 
flexor;  for  the  tendon  of  the  long  flexor  coming  round  the 


260 


MUSCLES  MOVING  I'HE  TOES. 


inner  circle,  runs  obliquely  outwards  to  reach  the  toes,  while 
the  short  flexor  coming  from  the  heel,  which  is  towards  the 
outer  edge  of  the  foot,  runs  in  a like  degree  obliquely  im 
wards  and  meets  the  other  at  an  acute  angle  near  the  toes. 

CXCIII.  The  LuniBRiCALEs  must  be  dissected  after  the 
§hort  flexor.  They  need  no  description,  since  they  exactly 
correspond  with  those  of  the  hand.  They  rise,  like  them,  in 
the  forks  of  the  flexor  tendons.  They,  like  them,  pass  through 
the  digitations  of  the  aponeurosis.  They  pass  on  to  the  first 
bone  of  the  toes,  and,  like  the  lumbricales  of  the  hand,  creep 
over  the  convexity  of  the  bone,  to  be  united  along  with  the 
tendons  of  the  extensors.  Their  insertion  is  always  at  the 
side  of  the  toe  next  the  great  toe,  and  their  use  is  to  bend  the 
first  joint  of  the  toes,  and  to  draw  them  towards  the  great  one, 
making  an  arch  in  the  foot,  and  assisting  the  transversalis 
pedis.  The  flexor  brevis  lies  most  superficially  upon  the 
sole  of  the  foot,  having  its  origin  from  the  inner  surface  of  the 
aponeurosis.  The  massa  carnea  lies  deeper,  having  no 
origin  but  from  the  tip  of  the  heel-bone,  and  being  soon  im- 
planted into  the  tendon  of  the  long  flexor.  The  lumbricales 
again  rise  from  the  tendons  of  the  long  flexor,  beginning  just 
where  the  massa  carnea  ends  in  it:  and  the  lumbricales  are 
the  flexores  primi  intemodii;  the  short  flexor  muscle,  the 
flexor  secundi  intemodii ; the  long  flexor,  the  flexor  tertii 
intemodii  digitorum. 


EXTENSORS  OF  THE  TOES. 

CXCIV.  The  EXTENSOR  LONGus  DIGITORUM  PEDIS  is  Very 
difficult  to  dissect,  from  its  numerous  adhesions. 

It  arises  properly  from  the  head  of  the  tihia,  at  its  outer  and 
forepart,  just  under  the  Imee  ; but  it  has  also  strong  adhesions 
to  the  inner  surface  of  the  fascia,  to  the  tendinous  partitions 
betwixt  it  and  the  tibialis  anticus  before  and  betwixt  it,  and 
the  peronasi  behind,  and  also  to  the  interosseous  ligament, 
and  to  the  edge  of  the  fibula.  Its  small  origin  soon  becomes 
thick,  and  is  divided  even  from  the  beginning  very  perceptibly 
into  three  distinct  portions.  These  soon  form  three  round 
tendons,  which  go  obliquely  inwards,  pass  under  the  annular 
ligament  of  the  ankle,  and  run  in  a ring  of  it,  peculiar  to 
them  and  the  peronaeus  tertius.  They  then  traverse  the  two 
bands  of  the  annular  ligament,  upon  the  forepart  of  the  foot, 
and  now  they  change  their  direction  a little,  and  go  from 
within  outwards,  and  diverge  towards  their  proper  toes. 
There  are  three  portions  of  muscle,  and  four  toes  to  b€ 


MUSCLES  MOVING  THE  TOES. 


261 


moved ; the  first  portion  divides  its  tendon  into  two,  at  the 
joint,  so  that  the  first  portion  serves  both  the  first  and  second 
toe,  the  second  the  third  toe,  and  the  third  serves  the  fourth 
toe.  Here  the  tendon  of  the  long  extensor  receives  four  other 
tendons  ; first,  of  the  interossei  externi ; secondly,  of  the 
interrossei  intern! ; thirdly,  of  the  long  flexor ; fourthly,  of 
the  lumbricales ; and  these  form  a very  large  sheath,  quite 
surrounding  the  toe. 

These  do  not  only,  like  other  extensors,  extend  the  toes, 
but  also,  by  the  divergence  of  the  tendon,  expand  them,  or 
separate  them  one  from  another. 

CXCV.  The  EXTENSOR  digitorum  brevis  is  so  connected 
with  the  extensor  longus,  that  it  is  natural  to  describe  them 
together.  It  is  placed  just  where  the  buckle  lies,  upon  the 
ri^ng  of  the  foot,  having  its  origin  from  the  heel-bone,  and 
running  obliquely  inwards. 

Its  origin  is  from  the  outer  side,  and  forepart  of  the  heel- 
bone,  and  also  from  part  of  the  annular  ligament.  It  is  smaller 
where  it  arises  by  a short  tendon  from  the  heel-bone,  but  it 
gradually  encreases  in  size  ; it  divides  early  into  four  heads, 
which  are  muscular,  and  very  distinct ; the  two  inner  of  which 
are  larger,  the  two  outer  more  slender  : each  head  has  already 
formed  an  oblique  tendon  under  its  flesh,  which  begins  to 
appear  naked  about  half  way  down  the  metatarsal  bones. 
These  tendons  cross  those  of  the  long  extensor,  and  pass 
under  them  nearly  about  the  end  of  the  metatarsal  bones. 
Then  one  is  implanted  into  the  first  bone  of  the  great  toe,  and 
on  the  inside  of  the  long  tendon  under  which  it  had  turned. 
The  second,  third,  and  fourth  tendons  are  inserted  into  their 
respective  next  toes,  and  the  little  toe  is  left  without  one. 
The  three  last  of  these  tendons  form  a sort  of  slit,  the  two 
sides  of  which  pass  along-  the  sides  of  the  toes,  surrounding 
the  long  tendon,  something  like  a perforatus  ; so  that  the 
three  last  tendons  are  inserted  along  with  the  long  tendons  into 
the  last  bone  of  the  toes. 

The  obliquity  of  this  short  muscle  counteracts  the  obliquity 
of  the  long ; and  it  serves  to  extend  and  to  spread  the  toes, 
and  to  pull  them  away  from  the  great  toe. 

CXCVI.  The  EXTENSOR  poLE!Cis  PROPRius  is  a very 
slender  muscle  running  from  the  top  of  the  leg  to  the  second 
joinc  of  the  great  toe.  It  arises  from  the  fibula,  a little  below 
its  head,  takes  fibres  from  the  interosseous  ligament,  grows 
tendinous  as  it  approaches  the  foot,  then  passing  under  the 
annular  ligament,  and  the  cross  ligament  of  the  foot,  it  goes 
onwards  to  the  second  joint  of  the  toe  over  the  first. 

The  succession  in  which  these  muscles  lie,  under  and  be- 


262 


MUSCLES  MOVING  THE  TOES. 


hind  each  other,  is  this ; first,  the  tibialis  anticus,  the  outei- 
most  muscle,  arises  from  the  forepart  of  the  tibia,  nearest 
the  forepart  of  the  leg,  at  the  ridge  of  the  tibia  : secondly, 
the  extensor  pollicis  lies  immediately  behind,  and  under  the 
tibialis  anticus;  thirdly,  the  extensor  digitorurn  communis 
lies  behind  that : and  fourthly,  the  peroneus  tertius  lies  behind 
the  common  extensor,  like  a part  of  that  muscle. 

These  extensor  tendons  are  bound  down  by  cross  bands, 
resembling  the  annular  ligaments  of  the  wrists.  The  general 
fascia  of  the  thigh  is  continued  over  the  knee,  and  dowm  the 
leg : it  is  much  strengthened  at  the  knee,  where  it  adheres  to 
each  point  of  bone  ; it  descends  very  thick  and  strong  over 
the  leg,  binding  down  and  strengthening  the  tibialis  anticus 
and  extensor  muscles.  The  sheath  grows  thinner  towards  the 
ankle,  but  where  it  passes  over  the  joint  it  is  so  remarkably 
strengthened  by  its  adhesions  to  the  outer  and  inner  ankles, 
that  it  seems  to  form  two  distinct  cross  bands,  which,  going 
from  the  point  of  the  outer  ankle,  across  the  extensor 
tendons,  to  the  point  of  the  inner  ankle,  forms  a strong  crucial 
ligament,  i-esembling  the  annular  ligament  of  the  wrist ; so 
that  this,  which  is  called  the  ckucial  ligament  of  the  ankle 
or  foot,  is  plainly  but  a strengthening  of  the  common  sheath. 

The  remaining  muscles  in  the  foot  are  the  interossei, 
which,  in  the  foot,  are  found  single  on  the  lower  surface  or 
sole,  but  double,  and  two-headed  upon  the  upper  part  of 
the  foot.  The  abductor,  flexor,  and  adductor  pollicis, 
which  surround  the  great  toe,  something  like  those  of  the 
thumb;  and  the  abductor  and  flf.xob  minimi  digiti,  sur- 
rounding the  little  toe  ; and  there  is  a small  slip  of  muscle, 
the  TRANsvERSALis  PEDIS,  whicli  gocs  across  the  sole  of  the 
foot. 

CXCVII.  The  ABDUCTOR  pollicis  arises  by  very  short 
tendinous  fibres  from  the  knob  of  the  os  calcis,  and  also  from 
a ligament  which  stretches  from  this  knob  to  the  sheath  which 
belongs  to  the  tibialis  posticus  ; and  it  arises  also  from  the  ten- 
dinous partition  betwixt  it  and  the  short  flexor  of  the  toes;  and 
although  it  forms  a tendon  beginning  opposite  to  the  cunei- 
form bone,  the  tendon  is  not  naked,  till  it  has  reached  the  mid- 
dle of  the  long  metatarsal  bone.  It  unites  with  the  short  flex- 
or of  the  same  toe,  and  is  inserted  into  the  first  bone  or  phalanx 
of  the  toe  at  its  root,  and  os  sesamoideum.  Its  use  is  to  pull 
aside  the  toe,  and  at  the  same  time  to  bend  it  a little  ; it  also 
curves  the  foot  itself,  for  a joint,  or  any  loaded  part,  is  much 
better  supported  by  muscles  than  by  ligaments;  and  this  arch 
requires  support  more  than  almost  any  other  part. 


MUSCLES  MOVING  THE  TOES.  26^ 

CXCVIIL  Flexor  BREVIS  POLLicis.  This  muscle  is  much 
shorter  than  the  last,  and  lies  betwixt  the  abductor  and  the 
adductor;  it  lies  immediately  upon  the  metatarsal  bone. 

Its  origin  is  by  a pretty  long  tendon  from  the  heel-bone,  and 
from  the  os  cuxeiformi-  externum,  by  two  separate  slips, 
from  the  heel-bone,  being  a full  inch  in  length  ; it  also  adheres 
to  the  membranous  partitions  on  either  side  of  it.  It  is  soon 
divided  into  turn  heads  ; one  goes  to  the  abductor,  and  the 
other  goes  to  the  adductor,  to  have  the  tendons  inserted  with 
theirs,  into  the  root  of  the  first  bone  or  phalanx.  These  ten- 
dons contain  the  sesamoid  bones  ; and  the  parting  of  the  two 
heads  makes  a channel  for  the  tendon  of  the  long  flexor  to  run 
in. 

Its  use  is  to  bend  the  first  joint  of  the  great  toe. 

CXCIX.  The  ADDUCTOR  pollicis  is  the  third  and  last  por- 
tion of  the  muscle  which  encircles  the  great  toe. 

It  arises  from  the  heel-bone,  by  a tendon  as  long  almost  as 
that  w'hich  it  gives  the  abductor : it  does  not  immediately  arise 
from  the  heel-bone ; but  there  is  a ligament  extended  from  the 
heel-bone  to  the  os  cuboides,  and  it  arises  from  that  ligament : 
this  is  the  ligament,  under  which  the  tendon  of  the  peroneus 
longus  glides.  It  takes  likewise  an  origin  from  the  cuneiforme 
externum.  The  adductor  is  divided  into  two  fleshy  fasciculi 
or  heads  ; these  unite,  and  going  obliquely  inwards,  are  inserted 
either  into  the  sesamoid  bone,  or  directly  into  the  first  bone  of 
the  great  toe. 

CC.  The  TRANsvERSALis  PEDIS  cxtends  transversely  across 
the  sole  of  the  fbot,  at  the  head  of  the  metatarsal  bones ; it  is 
a very  small  muscle,  and  resembles  a good  deal  the  palmaris 
brevis. 

It  arises  from  the  forepart  of  the  metatarsal  bone  of  the 
great  toe,  and  the  sesamoideum  internum,  and  is  inserted  into 
the  under  and  outer  part  of  the  anterior  extremity  of  the 
metatarsal  bone  of  the  little  toe  and  ligament  of  the  next  toe. 

Its  use  is  said  to  be,  to  make  a sort  of  gutter  in  the  foot,  by 
drawing  the  beads  of  the  metatarsal  bones  together;  but  is  it 
not  evident,  that  this  is  one  of  many  instances  of  muscles  be- 
ing a more  perfect  suppoi't  than  ligaments.^ — It  is  a support, 
having  a sort  of  intelligence,  contracting  or  relaxing,  according 
to  the  necessity  or  degree  of  force ; indeed,  except  this  use,  it 
is  not  easy  to  assign  any,  for  there  is  very  little  occasion  for 
hollowing  the  foot  in  this  direction- 

CCI.  The  ABDUCTOR  MINIMI  DiGiTi,  like  the  abductor  pol- 
licis,  is  a pretty  long  muscle,  but  very  slender,  lying  on  ihe 
outer  side  of  the  foot. 


264  MUSCLES  MOVING  THE  TOES. 

Its  origin  is  from  the  knob  of  the  heel-bone,  and  from  the 
tendinous  septum,  which  covers  the  flexor  brevis  : it  forms  two 
small  tendons  in  the  same  direction  : one  small  and  shorter 
tendon  is  fixed  into  the  metatarsal  bone,  at  its  root : the  other 
goes  forward,  to  be  inserted  into  the  root  of  the  first  bone  of 
the  toe,  so  that  this  muscle  clearly  performs  both  the  offices 
ascribed  to  the  other  flexors.  It  bends  the  toe  to  which  it  be- 
longs, and  it  extends  and  supports  the  tarsus  in  walking ; and 
it  carries  the  toe  a little  outwards,  from  which  it  has  its  name. 

cell.  The  FLEXOR  BREVIS  MINIMI  oiGiTi  is  ncxt,  and  is 
almost  the  same  muscle  in  place  and  office  : it  is  an  exceeding- 
ly small  muscle  ; it  just  measures  the  length  of  the  metatarsal 
bone,  and  arises  from  it.  Its  origin  is  from  the  root  of  the 
metatarsal  bone  of  the  little  toe,  and  from  the  ligament  by 
which  that  bone  is  connected  with  the  os  cuboides ; its  small 
belly  runs  the  length  of  that  bone,  and  it  is  implanted  by  a short 
tendon,  into  the  root  of  the  first  bone  of  the  little  toe. 

Its  use  is  to  bend  the  toe. 

CCIII.  The  iNTEROssEi  iNTERNi  are  three  small  muscles, 
seated  in  the  planta  pedis,  as  the  interossei  manus  are  in  the 
palm  of  the  band.  Their  slender  tendons  pass  through  the 
openings  of  the  aponeurosis  plantaris,  and,  going  on  the  inside 
of  the  toes,  are,  like  the  lumbricales,  inserted  along  with  the 
extensor  tendons. 

These  pull  the  toes  towards  the  great  toe,  bend  the  first  joint, 
and  extend  the  second  and  third. 

CCIV.  The  INTEROSSEI  EXTERNi  are,  like  the  correspond- 
ing muscles  of  the  hand,  four  in  number,  and  double  headed, 
and  have  been  named  bicipites.  They  rise  from  the  metatar- 
sal bones,  on  each  side  of  them  : each  has  some  little  variety 
in  its  origin  or  course  ; but  it  is  far  from  being  worth  our  while 
to  describe  each  individually,  as  many  do  : it  is  sufficient  to 
observe  their  origin,  and  that  their  tendons  all  meet  the  ten- 
dons of  the  long  and  short  extensors  of  the  lumbricales,  and 
of  the  INTEROSSEI  INTERNI,  upoo  the  backs  of  the  toes ; so  that 
the  whole  forms  a web,  aponeurosis,  or  sheath,  which  covers 
the  upper  part  of  the  toe,  and  adheres  to  its  point. 

The  office  of  these  muscles  is  to  extend  the  toes. 

Plantar  aponeurosis. — The  palm  and  the  sole  are  much 
exposed,  and  are  specially  defended  by  a thick  tendinous 
aponeurosis.  In  the  palm,  there  is  the  more  reason  to  suspect 
expansion  to  proceed  from  the  tendon  of  one  muscle,  because 
the  tendon  of  the  palmaris  is  inserted  into  it ; yet  that  is  not 
probable  ; for  the  tendon  is  very  slender,,  and  quite  unfit  for  the 
generation  of  so  broad  a sheet  of  aponeurosis.  In  the  foot, 
such  an  origin  is  ?=^tillless  probable;  for  the  plantaris  tendon 


MUSCLES  MOVING  THE  TOES.  265 

does  not  terminate  in  the  plantar  aponeurosis,  but  is  inserted 
into  the  heel-bone. 

The  plantar  aponeurosis  arises  most  distinctly  from  that  part 
of  the  tuber  of  the  heel-bone  upon  which  we  stand  : it  is  divid- 
ed into  three  sheaths.  Sabatier  makes  a middle,  external, 
and  internal  portion  of  the  same  aponeurosis.  Albinus  also 
describes  it  as  three  distinct  aponeurosis ; one  for  the  middle 
of  the  foot ; one  for  the  abductor  of  the  great  toe  ; and  one  the 
aponeurosis  of  the  abductor  of  the  little  toe;  all  connected 
together  only  by  their  edges.  Cowper  considers  it  as  a general 
expansion  from  the  plantaris ; and  it  is  from  this  prejudice 
that  the  muscle  has  its  name. 

But  its  true  origin  is  from  that  part  of  the  knob  of  the  heel- 
bone  on  which  we  stand.  The  middle  and  more  pointed  ten- 
don arises  from  the  very  point  of  the  knob.  The  inner  fascia 
arises  from  the  inside  of  this;  and  the  outer  one  from  the  out- 
side. And  though  thus  divided  into  three  heads,  yet  the  whole 
origin  is  from  the  heel-bone.  From  this  point  the  aponeurosis 
goes  forward,  expanding  till  it  is  as  broad  as  the  roots  of  the 
toes  ; so  that  the  whole  has  the  shape  of  a sandal;  and  as  it 
expands,  its  fibres  are  scattered,  so  as  to  have  a radiated 
appearance.  Accordingly  the  part  nearest  the  heel  is  thicker, 
while  the  broader  part  is  thinner. 

It  goes  forward  like  the  sole  of  a shoe,  till  having  approached 
the  heads  of  the  metatarsal  bones,  it  is  divided  into  five  heads, 
corresponding  with  the  five  knobs ; and  each  of  these  heads 
again  subdivides  itself  in  two  bands,  which,  passing  on  each 
side  of  the  heads  of  the  metatarsal  bones,  is  fixed  into  the  sides, 
so  as  to  leave  room  for  the  passing  of  the  tendons,  and  nerves, 
and  arteries. 

Now  this  middle  aponeurosis  sends  down  a deep  strong 
partition  on  each  side  of  it ; which  is  the  best  reason  that  I 
know  for  making  these  three  distinct  aponeurosis;  for  by  these 
perpendicular  partitions,  the  hollow  of  the  foot  is  separated 
into  three  distinct  chambers : under  the  middle  one  are  con- 
cealed the  tendons  of  the  long  flexors,  with  the  luinbricales 
and  short  flexor  muscles : under  the  outer  one  the  flexor  and 
abductor  of  the  little  toe  : and  under  the  inner  one  the  ad- 
ductor, flexor,  and  the  abductors  of  the  great  toe. 

The  uses  of  this  great  and  very  strong  aponeurosis  are  : that 
it  protects  all  the  parts,  <he  blood  vessels,  muscles,  and  nerves 
that  lie  under  it:  that  it  supports  the  arch  of  the  foot,  both  in 
standing  and  in  motion,  passing  from  heel  to  toe  like  a bow- 
string across  its  arch  : that  it  binds  down  the  muscles,  and 
consequently  supports  and  assists  them  in  their  strong  actions  : 
that  it  gives  origin  or  part  of  their  origin,  to  many  of  the  mus^ 

VOL.  I.  ‘ LI 


OF  THE  MUSCULAR  POWER. 


266 

cles  ; wliicb,  by  their  frequent  and  irregular  adhesion  to  it,  are 
very  difficult  to  dissect  : that  it  forms  openings  or  rings,  in 
'vhich  the  tendons  of  the  other  muscles  pass. 


CHAP.  IX. 

OF  THE  MUSCULAR  POWER. 

That  contractile  power  which  resides  in  the  muscular  os' 
living  fibre,  is  a phenomenon  the  most  wonderful  and  perplex- 
ing of  all.  When  we  cannot  reach  the  true  point,  the  mind  too 
often  condescends  to  the  most  trifling  pursuits  ; and  so,  when 
the  older  physiologists  could  not  understand  the  intrinsic  nature 
of  this  muscular  power,  they  endeavoured  to  discover  the  size, 
the  colour,  and  other  external  properties  of  the  fibre  ; foolishly 
desiring  to  knov/,  what  if  known,  could  be  of  no  avail.  Colour  was 
believed  to  be  essential  to  the  constitution  of  a muscle : but  in 
fowls,  in  amphibious  animals,  in  fishes,  in  worms,  and  insects, 
through  all  the  gradations  of  animals  of  different  species  or  dif- 
ferent sizes,  the  colours  of  the  m uscular  fibre  change.  In  fishes  and 
in  insects,  it  is  entirely  white ; even  in  the  human  body,  it  is 
not  essentially  red  : the  blood  which  makes  the  fibre  red  may 
be  washed  away.  Then  why  should  we  define  a muscle  by 
that  accidental  property  which  it  so  often  wants,  and  of  which 
it  may  be  so  easily  deprived,  while  we  may  define  it  more 
truly  by  its  contractile  power,  the  only  evidence  of  its  nature, 
and  its  chief  distinction  in  the  system  ; for  the  contraction  of 
the  iris  constitutes  its  nature ; it  is  a muscle  by  truer  marks 
than  by  its  colour:  and,  by  the  same  rule,  the  muscles  of  the 
least  insect  are  as  perfect  as  the  muscles  of  a man. 

Philosophers  of  the  last  age  had  been  at  infinite  pains  to  find 
the  ultimate  fibre  of  muscles,  thinking  to  discover  its  properties 
in  its  form  ; but  they  saw  just  in  proportion  to  the  glasses  which 
they  used,  or  to  their  practice  and  skill  in  that  art,  which  is 
now  almost  forsaken.  Some  found  the  fibres  to  be  of  one 
equal  size  in  all  creatures,  however  various  : others  found  them 
them  proportioned  to  the  size,  or  age,  or  strength,  of  their  sub- 
ject; but  even  such  discrepancies  are  trivial  to  those  which,  in 
one  of  the  greatest  of  these  minute  philosophers,  are  found  al- 
most in  the  same  page;  sometimes  affirming  the  ultimate  fibre  to 
be  greater  or  smaller,  according  to  the  strength  of  the  subject. 


OF  THE  MU3CDLAR  POWER.  267 

and  again  making  them  of  equal  size,  in  the  whale  and  in  the 
insect. 

Others,  less  troubled  about  the  ultimate  size  of  these  fibres, 
had  conceived  notions  of  their  form,  which,  in  the  credulity  of 
the  times,  rose  into  the  importance  of  doctrines,  and,  from  the 
first  raw  conceptions  of  their  authors,  were  finally  proved  by 
the  microscope,  forsooth ; and  while  one  author  was  drawing 
his  rhomboidal  fibres,  all  conjoined  in  regular  succession,  and 
another  describing  them  also  from  the  microscope,  as  consist- 
ing of  six  cylindrical  fibres,  involved  in  a spiral  one,  a third 
reckoned  the  fibres  a succession  of  spherical  bodies  : and 
Cowper  thought  that  he  was  injecting  with  quicksilver,  chains 
of  bells  jointed  with  each  other.  For  the  honour  of  the  age, 
these  vanities  are  forgotten  now.  And  why,  indeed,  should  we 
seek  the  ultimate  fibres  of  the  muscle,  or  study  their  forms, 
when  the  discovery  could  not  advance  us  one  single  step  in  the 
knowledge  of  its  nature  or  essence  ? What  avails  it  that  we 
have  discovered  (if  we  have  really  discovered)  the  shape  of 
the  particles  of  the  blood  ; the  wave-like  fibres  within  the  sub- 
stance of  the  nerves  ; or  the  jointed  appearance  in  the  smaller 
fibres  of  muscles.^  We  do  not  understand  the  nature  of  the 
blood,  the  properties  of  the  nerves,  nor  the  contractile  power 
of  the  muscles  at  all  better  by  this  peculiar  form  of  the  internal 
structure,  than  we  do  by  the  grosser  marks  of  their  external 
form. 

Physiologists  have,  by  a late  sense  of  their  own  weakness, 
been  at  last  humbled  to  this  becoming,  but  unwilling  acknow- 
ledgement, that  this  contractility  of  the  muscles  is  an  original 
endowment  of  this  living  matter  derived  from  the  Creator, 
imparted  in  a w’ay  which  we  cannot  know,  and  so  attached  to 
the  organization  of  the  muscular  fibre,  that  where  its  organiza- 
tion is  destroyed,  this  power  is  lost.  We  have  resigned  the 
search  after  a mechanical  or  physical  cause,  and  seek  only  to 
learn  the  properties  of  this  living  power,  and  the  excitements 
by  which  it  is  moved.  To  this  end  it  is  necessary  to  define  this 
power,  distinguishing  it  from  those  feelings  or  motions  which 
result  from  the  nerves..  The  vis  insita,  being  that  power  which 
belongs  to  muscles,  is  the  source  of  motion  and  animal  life. 
The  vis  nervea,  being  that  property  which  is  peculiar  to  nerves, 
is  the  seat  of  feeling,  and  the  cause  of  voluntary  motion,  rela- 
ting chiefly  to  the  enjoyments  and  consciousness  of  life  ; for 
life  and  motion  exist  even  in  plants,  and  in  many  creatures, 
which,  not  having  nerves,  harve  neither  consciousness  nor  en- 
joyment, and  in  which  the  place  of  feeling  is  supplied  by  a 
less  perfect  instinct,  by  this  vis  insita,  or  some  analogous  inhe.- 
rent  power. 


OF  THE  MUSCULAR  POWER. 


268 

This  iiritable  power  residing  in  muscles,  may  be  defined 
the  property  by  which  muscles  feel  and  re-act,  upon  certain 
stimuli  being  applied,  without  that  feeling  being  conveyed  to 
the  sensorium,  without  a consciousness  of  action,  without  any 
other  natural  dependence  on  the  system  than  that,  while  cer- 
tain orders  of  muscles  are  obedient  to  their  own  stimuli  only, 
as  the  heart  to  the  blood,  other  orders  of  the  muscles  are  ready 
to  receive  the  commands  of  the  will.  And  above  all,  so  little 
dependent  is  this  action  upon  the  nerves,  that  it  is  as  perfect 
in  animals  which  have  no  nerves,  and  is  for  a time  very  perfect 
in  the  parts  which  have  been  severed  from  the  systems  to  which 
they  belonged.  This  power,  inherent  in  the  muscular  fibre, 
belonging  to  its  constitution,  and  not  derived  from  without,  is 
the  vis  insita,  or  irritability  of  Haller,*  the  vis  vitalis  of  Goerter, 
the  oscillation  of  Boerhaave,  and  the  tonic  power  of  Stahl. 
It  is  seen  in  the  spontaneous  and  tremulous  contractions  of 
muscles  when  lacerated  ; as  in  wounds,  when  cut  in  operations, 
when  entirely  separated  from  the  body ; as  in  experiments 
upon  animals,  like  that  tremulous  motion  which  we  often  feel 
in  various  parts  of  the  body,  wuthout  any  evident  cause,  and 
independent  of  the  will.  Even  when  the  body  is  dead  to  all 
appearance,  and  the  nervous  power  gone,  this  contractile 
power  remains ; so  that  if  a body  be  placed  in  certain  attitudes, 
before  it  be  cold,  its  muscles  will  contract,  and  it  will  be  fixed 
in  that  posture  till  the  organization  yields  and  begins  to  be  dis- 
•solved  ; it  is  the  same  inherent  power  by  which  a cut  muscle 
contracts  and  leaves  a gap.  This  is  but  a feint  indication  of 
that  latent  power,  which  can  be  easily  excited  to  the  most 
violent  motions,  and  on  which  all  the  strength  of  the  muscles 
depends  : for  the  ligaments,  tendons,  bursas  of  joints,  and  all 
those  parts  which  have  no  living  power,  are  capable  of  bearing 
the  same  weight  when  dead  as  when  alive.  But  such  is  the 
connection  betwixt  the  organization  of  a muscle  and  its  con- 
tractile power,  that  the  moment  it  dies  its  power  is  gone ; and 
the  muscle  whicli  could  lift  a hundred  pounds  while  alive,  can- 
not bear  the  weight  of  a few  pounds  when  dead.  This  latent 
power  may  be  brought  into  full  action  by  various  stimuli.  The 
latent  power  itself  is  called  vis  insita,  the  acting  power  put  into 
action,  or  the  proof  of  the  vis  insita,  upon  applying  stimuli,  is 
called  the  irritability  of  muscles.  This  irritability  is  so  far  in- 

* Tlie  ii'rilablity  of  a musde  is,  perhaps,  more  properly  the  vis  insita,  or  inherent  powc-i' 
•■ailrd  into  iimnediatp.  action,  by  tlie  presence  ofstimuli ; and  as  for  the  names  of  Tonic  Power , 
Vital  I’owcr,  and  the  rest,  'he  terms  are  quite  undefined,  and  may,  perhaps,  tiave  refinrec' 
■^thcr  to  tlie  combined  effect  of  ail  the  powers  of  life,  and  of  all  the  properties  of  inaniinalr 
matter,  of  nervous  sympathy,  elosticit}',  and  of  muscular  power  comhiaed. 


OF  THE  MUSCULAR  POWER. 


269 


dependent  of  nerves,  and  so  little  connected  with  feeling,  which 
is  the  province  of  the  nerves,  that  upon  stimulating  any  muscle 
by  touching  it  with  a caustic,  or  irritating  with  a sharp  point, 
or  driving  the  electric  spark  through  it,  or  exciting  with  the 
metallic  conductors,  as  of  silver  and  zinc,*  the  muscle  instantly 
contracts ; although  the  nerve  of  that  muscle  be  tied,  although 
the  nerve  be  cut  so  as  to  separate  the  muscle  entirely  from  all 
connection  with  the  system,  although  the  muscle  itself  be  se- 
parated from  the  body,  although  the  creature  upon  which  the 
experiment  is  performed  may  have  lost  all  sense  of  feeling, 
and  have  been  long  apparently  dead.  Thus,  a muscle  cut 
from  the  limb,  trembles  and  palpitates  for  long  after;  the 
heart  separated  from  the  body  contracts  when  irritated ; the 
bowels  wiien  torn  from  the  body  continue  their  peristaltic  mo- 
tion, so  as  to  roll  upon  the  table,  ceasing  to  answer  to  stimuli 
only  when  they  become  stiff  and  cold ; and  too  often  in  the 
human  body  the  vis  insita  loses  the  exciting  power  of  the 
nerves,  and  then  palsy  ensues;  or,  losing  all  the  governance 
of  the  nerves,  the  visinsista,  acting  without  this  regulating  pow- 
er, falls  into  partial  and  general  convulsions.  Even  in  vegetables, 
as  in  the  sensitive  plant,  this  contractile  power  lives.  Thence 
comes  the  distinction  betwixt  the  irritability  of  muscles  and 
the  sensibility  of  nerves ; for  the  irritability  of  muscles  sur- 
vives the  animal,  as  when  it  is  active  after  death  ; sui’vives  the 
life  of  the  part,  or  the  feelings  of  the  whole  system,  as  in  uni- 
versal palsy,  where  the  vital  motions  continue  entire  and  per- 
fect, and  where  the  muscles,  though  not  obedient  to  the  will, 
are  subject  to  irregular  and  violent  actions ; and  it  survives 
the  connection  with  the  rest  of  the  system,  as  where  animals 
very  tenacious  of  life  are  cut  into  parts:  but  sensibility,  the 
property  of  the  nerves,  gives  the  various  modifications  of  sense, 
as  vision,  hearing,  and  the  rest ; gives  also  the  general  sense 
of  pleasure  or  pain,  and  makes  the  sj^stem,  according  to  its 
various  conditions,  feel  vigorous  and  healthy,  or  weary  and 
low.  And  thus  the  eye  is  sensible,  and  the  skin  is  sensible ; 
but  their  appointed  stimuli  produce  no  motions  in  these  parts; 
they  are  sensible,  but  not  irritable.  The  heart,  the  intestines, 
the  urinary  bladder,  and  all  the  muscles  of  voluntary  motion, 
answer  to  stimuli  with  a quick  and  forcible  contraction ; and 
yet  they  hardly  feel  the  stimuli  by  which  these  contractions 
are  produced,  or  at  least  they  do  not  convey  that  feeling  to 
the  brain.  There  is  no  consciousness  of  present  stimulus  in 

* See  a most  iogenious  dissertation  by  my  pupil  Mr.  Fowler,  the  first  writer  io  this  coun 
tiT,  on  this  very  interesting  no\  eIty,  wliere  ttie  operations  of  this  new  excitement  are  ex 
plained. 


270 


OP  THE  MUSCULAR  POAVER. 


those  parts  which  are  called  into  action  by  the  impulse  of  the 
nerves,  and  at  the  command  of  the  will ; so  that  muscular 
parts  have  all  the  irritability  of  the  system,  with  but  little  feel- 
ing, and  that  little  owing  to  the  nerves  which  enter  into  their 
substance  ; while  nerves  have  all  the  sensibility  of  the  system, 
but  no  motion. 

The  VIS  iNsiTA  is  a power  that  is  in  continual  force,  pre- 
serving the  parts  ready  for  their  proper  stimuli,  whatever  these 
may  be  : one  set  obeying  their  own  peculiar  stimuli  chiefly, 
w'hile  others  are  obedient  to  the  nervous  power,  and  the  in- 
fluence of  the  will.  1 he  heart  is  stimulated  by  the  quantity 
or  quality  of  its  blood ; the  stomach  by  the  presence  of  food  ; 
the  intestines  by  their  contents : the  urine  stimulates  the 
bladder ; the  venereal  appetite  stimulates  the  genital  system  ; 
the  foetus  stimulates  the  womb  ; and  the  voluntary  muscles  (if 
we  may  be  allowed  to  guess  at  a thing  so  little  known,)  are 
excited  by  the  nerves,  and  so  are  obedient  to  the  will ; for, 
to  our  limited  view,  the  nerves  seem  to  be  the  sole  messen- 
gers of  these  commands,  and  any  stimulus  to  the  nerves 
moves  the  muscles  like  the  commands  of  the  will.  The  ab- 
sence of  the  due  stimulus  to  each,  or  the  presence  of  the 
ordinary  stimuli  in  too  great  power,  will  excite  enormous  and 
irregular  motions,  as  fulness  of  blood  in  the  heart,  poisons  in 
the  stomach,  acrimonies  in  the  intestinal  canal,  or  the  passions 
of  anger  or  fear  in  the  system  of  the  voluntary  muscles.  The 
due  stimuli  preserve  their  right  tone  and  action  ; but  these 
violent  stimuli  hurt  their  irratibility,  or  moving  power ; the 
heart  acts  weakly  after  fevers  ; the  appetite  is  languid  after 
debauch  ; the  limbs  are  weakened  by  labour ; and  the  whole 
system  is  ruined  by  excess.  Thus,  the  functions  by  which 
the  system  lives,  the  heart,  the  stomach,  the  bowels,  and  the 
womb,  the  various  sorts  of  vessels  by  which  the  fluids  are 
conveyed,  are  providently  removed  from  the  influence  of  the 
will ; for  these  are  the  machines  of  the  system,  whose  motions 
could  not  stop,  must  not  be  interrupted,  nor  lowered,  nor  raised, 
but  must  move  and  act  according  to  the  needs  of  the  system. 
Not  left  to  the  irregularities  or  carelessness  of  voluntary 
motions,  they  are  governed  each  by  its  own  peculiar  stimulus, 
and  act  in  a continued  and  equal  course. 

Thus,  there  are  in  the  body  two  living  powers,  which  are 
as  cause  and  effect  in  all  the  motions  of  our  system.  The 
NERVES  stand  as  an  intermedium  betwixt  all  external  objects 
and  our  general  sense  ; by  the  impressions  through  these 
come  pleasure  and  pain,  and  all  the  motives  to  action  ; by  the 
will,  returned  through  the  nerves,  all  voluntary  motions  ensue. 
Thus  are  the  nerves,  as  internuncii,  betwixt  the  external  im- 


OF  THE  MUSCULAR  POWER. 


271 


pression  and  the  moving  power.  But  nerves  were  never 
known  to  move  under  the  inGuence  of  stimuli ; the  moving 
power  is  another  property  of  a distinct  part  of  our  body, 
having  its  own  arrangement  of  particles,  and  its  own  peculiar 
form.  All  motion  then  proceeds  from  the  joint  operation  of 
either  power : the  nerves  convey  .he  impressions,  while  the 
muscles  contain  the  power  ; and  it  is  here,  as  in  other  natural 
effects,  the  external  cause  changes,  while  the  inherent  pro- 
perty, the  subject  of  its  operation,  remains  the  same.  The 
nervous  power  is  the  regulator  of  the  system  ; it  is  the 
property  suited  to  all  the  supports  of  life,  upon  which  they 
act,  and  by  which  they  maintain  their  power  over  our  body  ; 
but  is  subject  to  continual  changing  : it  rises  and  it  falls,  is  per- 
fect or  low;  but  the  energy  of  the  muscle,  which  is  to 
answer  to  this  power,  remains  ever  the  same,  while  its  orga- 
nization remains  : the  nervous  poweris  exhausted  and  languid  ; 
but  the  muscular  power  is  always  perfect,  always  ready  for 
the  excitement  of  stimuli,  or  for  the  commands  of  the 
will. 

There  is  (if  we  may  be  allowed  any  expression  so  loose  and 
indefinite)  the  will  of  the  system,  and  the  will  of  the  mind; 
it  is  the  will  of  the  system,  that,  through  the  medium  of  nerves 
of  wide  sympathy  and  consent,  governs  and  leads  in  harmony 
all  the  consenting  functions  of  the  body,  and  lowers  and  raises 
their  powers,  according  to  the  weakness  or  strength,  or  fulness 
or  wants  of  the  body ; while  the  will  of  the  mind  commands 
those  voluntary  motions,  which  it  is  its  choice  to  perform.  So 
natural  seems  that  notion  which  has  long  prevailed,  of  an 
archseus,  or  presiding  spirit,  which,  like  a latent  instinct  regu- 
lates and  preserves  the  system,  prompts  to  what  is  right,  and 
creates  an  aversion  to  what  is  wrong,  and  raises  or  allays  the 
actions  of  the  vital  organs,  preserving  the  system  in  health, 
and  striving  against  disease.  The  voluntary  muscles  are  put 
under  the  command  of  the  will,  while  the  involuntary  muscles, 
by  which  the  vital  organs  move,  are  insulated  and  mechani- 
eal,  and  depend  less  on  our  spiritual  part : for  life  and  exist- 
ence depend  less  on  feeling,  or  that  which  is  allied  to  our  spiri- 
tual part,  and  more  on  the  irritable  and  moving  power ; and  it 
was  fit  that  this  irritable  power  should  be  divided  from  our  feel- 
ings and  our  will,  which  are  irregular  and  transitory,  and  apt 
rather  to  derange  than  to  preserve  the  system. 

How  this  division  is  accomplished,  we  do  not  know  in  any 
surer  way ; but  we  see  that  the  heart,  the  lungs,  the  stomach, 
and  the  intestines,  have  a proportion  of  nerves,  so  much  lower 
than  the  muscles  of  voluntary  motion,  that  their  very  existence 
lias  been  denied.  Yet  there  are  nerves  proper  to  the  vital 


272 


OF  THE  MUSCULAR  POWER. 


parts;  the  phrenic  nerve  goes  to  the  diaphragm  ; the  par  va~ 
gum  to  the  heart,  lungs,  and  stomach  ; the  sympathetic  nerve  j 
to  the  heart,  to  the  intestines  and  other  viscera  ef  the  abdo- 
men : these  nerves  are  appropriated  and  distinct.  Now,  this 
question  occurs : if  the  irritable  power  be  in  these  organs,  if  ! 
they  be  endowed  with  the  quality  of  feeling  their  own  peculiar  I 
stimuli,  and  answering  to  their  impulses,  what  need  is  there 
for  nerves  ^ but  they  also  have  their  nerves,  that  they  may  not 
want  some  living  connection  with  that  system  to  which  they  [ 
belong  : that  they  may  flourish  in  its  health,  and  languish  inks 
diseases;  that  they  may  act  according  to  the  needs,  and  be 
subject  to  the  will  of  the  system  ; that  the  grand  movers  of 
the  mechanical  system  may  be  affected  in  their  turns  by  the 
spiritual  part,  and  thus  the  digestion,  the  circulation,  the  vene- 
real appetite,  and  every  vital  power,  are  languid  and  depressed, 
or  lively  and  perlect,  according  lo  the  conditions  of  the  whole  : 
and  bow  these  functions  are  moved  by  anger,  or  joy,  or  fear, 
needs  not  be  told.  But  the  vital  functions  also  lose  their  ac- 
tion : “The  heart  acts  weakly  after  fevers;  the  appetite  is 
languid  after  a debauch  ; the  limbs  are  weakened  by  labour; 
and  the  whole  system  is  ruined  by  excess.”  These  organs 
have  less  dependence  on  nerves,  and  so  suspicions  arise,  that 
the  irritable  power,  the  very  basis  of  life,  may  also  fail  ; but 
how  should  it  fail  ^ If  the  motions  of  our  system  cease,  it  I 

must  be  either  from  the  incapacity  of  the  muscles,  or  from  the 
loss  of  exciting  power  in  the  nerves.  The  nerves  are  liable  ^ 
to  change,  but  the  muscle  retains  its  power  till  its  organization 
be  destroyed.  When  the  irritable  power  of  a muscle  ceases, 
when  the  heart,  for  instance,  begins  to  fail,  whence  can  that 
loss  arise  ? Its  power  is  not  mechanically  exhausted,  else  from 
what  source  could  it  ever  be  renewed  It  is  not  from  any 
injury  to  its  nerves ; for  the  heart,  when  cut  out  from  the  body, 
may  be  wearied  out  wnth  constant  stimuli,  till  it  cease  to  act; 
and  it  will  recover  by  rest,  without  communication  with  the 
nerves  : but  it  is  perhaps  such  a derangement  as  happens  in  a 
spring,  which,  being  long  bent,  loses  of  its  elastic  power:  the 
arrangement  of  its  particles  suffers  by  straining ; they  are  com- 
posed by  rest : and  if  the  elastic  power  be  thus  restored  in  an 
inanimate  spring,  much  more  should  the  contractile  pow'er  re- 
cover by  rest  in  the  muscular  fibres  of  a living  system. 

The  VIS  iNsiT.\  cannot  be  wearied  nor  exhausted  ; so  the 
heart  is  unwearied  in  its  function,  or  if  languid  or  too  violent 
ir  its  actions,  that  must  be  from  the  pow’er  of  stimulus  being 
lowered  or  increased,  not  from  any  change  on  the  inherent 
power.  The  voluntary  muscles  also  are  unwearied;  and  so, 
after  great  fatigue,  v/e  are  sensible  of  cramps  and  irregular  con- 


OF  THE  MUSCULAR  POWER. 


275 


tractions,  showing  that  they  are  still  active,  but  more  loosely 
governed  by  the  nerves,  and  not  so  fully  under  the  command 
of  the  will.  But  the  nervous  system  is  more  subject  to 
weariness  and  to  decay ; the  senses  become  tired  ; the  feelings 
of  the  system  are  exhausted.  It  is  from  this  failing  of  the 
nervous  power,  that  violent  exertions  bring  fatigue  and  pain  ; 
from  this  also  that  we  need  the  refreshment  of  sleep ; but 
during  sleep,  the  heart,  and  all  the  involuntary  muscles,  un- 
wearied in  their  functions,  proceed  still  in  the  same  regular  and 
orderly  course. 

This  irritability,  or  inherent  power,  not  only  keeps  the  mus- 
cles ready,  each  for  its  peculiar  stimulus,  but  preserves  a 
balance  over  the  whole  system  of  the  muscles.  We  know  that 
muscles  maintain  a constant  action,  independent  of  the  nerves. 
The  muscles  of  one  side  balance  the  opposite  muscles ; and  if 
the  muscles  of  one  side  be  relaxed  by  palsy,  the  action  of  the 
opposite  muscles  instantly  appears  : or  if  a limb  be  luxated, 
and  its  muscles  displaced,  they  persevere  in  a violent  and 
spasmodic  action,  till  they  be  restored  each  to  its  place.  Have 
we  not  reason  to  believe,  that  if  muscles  were  absolutely  and 
entirely  quiescent,  they  could  not  be  so  instantaneously  called 
into  action ; but  that  by  this  continual  tension  or  tone,  they 
more  readily  follow  the  commands  of  the  will : that  by  this 
lesser  tension,  they  are  prepared  for  greater  action,  and  inclined 
to  harmonize  ? for  if  all  the  muscles  were  quiescent,  and  one 
suddenly  moved  by  the  will,  its  antagonist  would  rise  into  undue 
action,  and  the  co-operating  or  assisting  muscles  would  be  un- 
prepared. Whereas,  by  this  continual  tension  of  all  the  mus- 
cles, one  set  is  opposed  to  another,  is  consenting  with  it,  and  is 
ready  to  co-operate  with  it,  or  to  oppose  it  in  the  due  degree  ; 
the  mind  has  but  to  incline  the  power  towards  one  set,  and 
immediate  and  orderly  motions  ensue. 

The  NERVOUS  INFLUENCE,  again,  is  as  a mere  stimulus  to 
the  voluntary  muscles,  as  blood  is  to  the  heart,  or  the  foetus, 
or  any  foreign  body  to  the  womb.  It  loses  its  influence  over 
the  system  faster  than  the  ordinary  powers  of  life  do;  and 
tbe  irritable  state  of  the  muscles  continues  long  after  the 
voluntary  motion,  or  the  power  of  excitement  from  the  nerves 
is  gone  : for  when  we  die  slowly,  this  inherent  power  is  exr 
hausted  in  the  struggles  for  life.  If,  while  in  perfect  health, 
we  are  killed  by  a sudden  blow,  the  irritable  power  of  the 
muscles  survives  the  nervous  system  many  hours  or  days,  and 
the  flesh  trembles,  and . the  absorbents  continue  to  absorb ; 
and  often,  as  after  suffocation,  we  can,  by  operating  upon 
this  poor  remains  of  life,  restore  the  circulation,  re-aiiimate 
the  nervous  system,  and  recover  that  life,  which  seemed  to 
VOL.  I.  M m 


,274 


OF  THE  MUSCULAR  POWER. 


have  entirely  left  the  body  ; and  thus,  the  nervous  influence,; 
which  seemed  to  animate  the  system,  and  to  be  the  prime 
mover  aixl  source  of  life,  owes  it  restoration  to  that  which 
was  thought  to  be  but  a secondary  power.  It  is  this  remains 
of  contractile  power  which  fixes  the  dead  body  in  whatever 
posture  it  is  placed  : it  is  this  remains  of  irritability,  which 
preserves  freshness  in  the  animal  which  seemed  dead,  but 
which  is  really  dying  still : for  the  moment  this  lingering  por- 
tion of  life  is  gone,  the  body  dissolves,  and  falls  down  5 and 
so  we  judge  of  freshness,  by  the  rigidity  of  the  flesh,  and 
foresee  approaching  putrefaction,  by  its  becoming  soft.  There 
is  no  putrefaction  in  creatures  suddenly  killed,  as  in  the  acci- 
dents which  happen  to  man,  or  in  killing  animals  by  a sudden 
blow ; in  these  the  body  continues  fresh  and  susceptible  of 
stimuli  long  after  death  : but  if  this  inherent  power,  this  irri- 
table nature  of  the  fibre,  be  exhausted  before  death,  or  in  the 
moment  of  death,  then  does  the  body  fall  quickly  into  the 
condition  of  dead  matter,  running  through  those  changes, 
which  are  the  only  true  marks  of  death.  The  fish,  which  is 
allod'ed  to  struggle  till  it  be  dead  ; the  ox,  over-driven  before 
it  be  brought  to  the  slaughter ; the  animal  killed  by  lightning, 
which  suddenly  explodes  (if  we  may  be  allowed  the  expres- 
sion) all  the  powers  of  life  ; in  these  the  contractile  power  is 
eflectually  exhausted ; no  mark  of  irritability  remains  ; putre- 
faction comes  quickly  on : and  so  in  those  who  die  of  the 
plague,  of  poison,  of  fevers,  or  of  any.  sudden  and  violent 
disease,  w'hich  at  once  extinguishes  life  in  the  vulgar  sense, 
and  robs  the  system  of  that  remnant  of  life,  which  the  physi- 
ologist could  produce  to  view ; in  all  these  cases,  the  body 
becomes  putrid  in  a few  hours.  If  a body  becomes  putrid  so 
early  in  warm  climates,  it  is  not  merely  because  putrefaction 
is  favoured  by  heat ; but  it  is  because  heat  exhausts  the  vital 
pow'er,  and  often  a part  of  the  body  has  lost  its  organized 
power,  and  is  almost  putrid  before  the  whole  be  dead.  We 
find,  that  we  are  wrong  in  this,  that  when  a body  has  lost  all 
feeling  and  motion,  we  pronounce  it  dead  ; the  nerves  indeed 
have  ceasfed  to  do  their  office ; all  feeling  and  consciousness  is 
gone;  but  the  mere  animal  power  survives  the  nerves,  and 
through  it  the  whole  system  may  be  recalled  into  perfect  life. 

The  powers  and  privileges  of  the  nervous  system  must  not 
be  ranked  too  high,  nor  valued  too  low  ; the  perfect  animal 
feels  and  moves  by  the  nervous  power ; but  surely  its  muscles 
are  actuated  by  a law  of  their  own  nature  : the  heart  of  the 
chick  begins  to  move,  before  we  dare  presume,  that  there  is 
any  organ  for  distributing  this  nervous  power.  The  punctum 
saliens,  is  the  heart  of  the  chick  : it  is  seen  beating  w'hile  the 


OF  THE  MUSCULAR  POWER. 


27o 

body  of  the  chick  is  but  a rude,  unformed,  and  gelatinous 
mass ; daily  this  active  centre  encreases  in  strength  and 
power;  and  it  has  a delicate  feeling  of  stimuli,  and  it  quickly 
re-acts,  so  as  “ to  fly  out  into  angry  and  perturbed  motions,” 
by  the  application  of  a stimulus.  It  is  excited  by  increased 
heat,  and  languishes  when  cold,  till  at  last  it  dies ; then  it 
ceases  to  act,  but  still  heat  restores  it  to  life  : and  is  not  the 
proof  stronger  in  the  grown  animal,  when  we  cut  out  the 
heart,  which  answers  to  stimuli  for  some  time  ; at  last,  seems 
to  have  its  power  exhausted ; it  lies  dead  for  some  time,  till 
it  again  recovers  its  power  ? If  this  power  proceeded  from  the 
nerves,  how  could  it  be  renewed  ? but  if  it  reside  in  the 
muscle  only,  it  may  have  been  wearied,  and  may  revive  ; its 
organization  may  have  been  deranged,  and  may  be  restored 
by  rest  from  stimuli  ; and  its  parts  may  be  composed  again, 
resuming  their  relative  situation,  and  their  active  arrangement 
and  form ; or  though  it  may  be  insensible  to  a stimulus  long 
applied,  it  may  be  still  alive,  even  to  a lower  stimulus  of 
another  kind ; or  it  may  awake  again  to  the  feeling  of  that 
stimulus,  which,  by  being  too  long  applied,  had  lost  its 
power.* 

Sensibility  depends  upon  the  nerves ; motion  on  the  mus- 
cles: both  are  equally  admirable  and  inscrutable;  the  one 
conducing  to  all  the  enjoyments  and  all  the  sufferings  of  life, 
and  to  the  intellectual  faculties  of  man  ; the  other  being  the 
chief  support  of  animal  life,  and  the  source  of  all  the  bodily 
powers. 

As  for  the  mechanical  powers,  by  which  the  contractions 
of  the  muscular  fibre  is  forwarded  or  retarded,  they  are  not  what 
they  have  been  believed  ; for  we  find  few  circumstances  in  the 
origin,  insertion,  or  forms  of  muscles,  to  favour  their  power, 
but  many  by  which  their  power  is  abridged.  There  are  cer- 
tain points,  where  the  length  of  lever  gives  an  encrease  of 
power.  The  mastoid  process  and  the  occiput  are  as  levers  for 
the  head  ; the  spines  of  the  vertebrse  for  the  back  ; the  olecra- 
non for  the  arm;  and  the  pisiform  bone  for  the  hand.  The 
pelvis,  and  the  jutting  trochanters  are  as  the  leVers  for  the 
thigh  ; the  patella  is  a lever  for  the  leg ; the  heel-bone  is  a 
lever  for  the  whole  foot ; and  the  arch  of  the  foot  is  as  a lever 

*_There  Is  a consideration  which  is  not  attended  to ; sf^sibilily  and  contractility  are  tw(> 
distinct  endowments  of  the  living  body,  the  one  the  property  of  the  nervous  matter,  tire 
other  of  the  luuacnlar  fibre.  Wlicn  a sharp  point  is  thrust  into  a muscle,  it  is  not  tlic 
muscular  fibre  wliich  feels  this  injury,  but  the  nervous  matter  in  intimate  distribution  with 
the  proper  fibre ; and  we  have  here,  no  more  than  on  other  occasions,  a proof  of  muscular 
■.  ontraction  being  the  direct  result  of  a stimulus  to  the  muscular  fibre.  Sensibility  must  re 
side  in  a part,  before  that  irart  be  capable  of  receiving  excitement,  the  contraction  of  the 
muscle  Is  ttieieforethe  conjoint  operation  of  the  nerves  and  muscular  fibres.  U.  B. 


276 


OF  THE  MUSCULAR  POWER. 


for  the  toes.  These  are  not  the  whole,  but  they  are,  perhaps, 
the  chief  levers  in  the  human  body.  In  all  the  other  implanta- 
tions the  muscle  is  fixed,  not  behind  the  joint,  but  betwixt  the 
joint  and  the  weight  that  is  to  be  moved.  There  is  a greater 
loss  of  power,  when  inserted  near  to  the  joint : there  is  less  loss 
of  power,  when  the  tendon  is  inserted  far  from  the  joint,  and 
though  we  call  such  insertion  a longer  or  shorter  lever,  there 
is  always  some  loss  of  power,  and  the  true  levers  in  the  body 
are  very  few  ; far  from  providing  mechanical  forms  to  encrease 
the  power,  nature  has  provided  such  a quantity  of  contractile 
power  as  to  compensate  for  any  loss  of  effect  : so,  in  place  of 
cncreasing  the  effect  of  muscles  by  levers,  pulleys  and  hinges, 
there  is  in  almost  every  muscle  a great  abatement  of  its  force, 
by  the  form  of  the  bones  which  it  is  destined  to  move  ; for 
muscles  lose  of  their  effect,  by  their  being  implanted,  not  be- 
hind the  joint,  but  betwixt  the  joint  and  the  body  to  be  moved  ; 
by  the  insertion  of  almost  all  muscles  being  very  oblique,  with 
respect  to  the  motions  which  they  are  to  perform,  so  that  half 
their  force  is  lost  upon  the  immoveable  end  of  the  bone.  Mucli 
force  is  lost  by  a muscle  passing  over  many  joints ; one  set  of 
fibres  in  a muscle  hinders  the  action  of  adjoining  fibres,  and 
every  degree  of  contraction  takes  from  that  muscle  an  equal 
proportion  of  its  power.  Thus,  every  where  in  the  human 
body,  is  power  sacrificed  to  the  form  and  fitness  of  the  part ; 
that  the  joints  may  be  smaller  than  the  limbs;  that  the  limbs 
may  be  proportioned  to  the  body  : and  beauty  and  convenien- 
cy  is  gained  by  the  sacrifice  of  that  power,  which  is  not  needed 
in  the  system,  since  the  wisdom  and  goodness  of  the  Creator 
has  appointed  a degree  of  force  in  the  muscles,  more  than 
proportioned  to  all  this  loss  of  the  mechanical  power.  Those 
who  will  admire  the  ways  of  Providence,  should  know  how  to 
admire  ! Nature  is  notseeking  to  compensate  for  want  of  power, 
by  the  advantages  of  pulleys,  and  levers,  and  mechanical 
helps  ; nor  is  it  in  the  forms  of  the  parts  that  the  Infinite  Wis- 
dom is  to  be  found  : for  among  other  gifts,  such  a portion  of 
this  spirit  is  given  to  man,  that  he  has  used  the  pulleys,  and 
levers,  accelerations  of  motion,  and  all  the  mechanical  powers 
that  result  from  it ; he  has  invented  valves  of  Infinite  variety, 
each  perfect  and  true,  to  its  particular  office  ; he  has  anticipa- 
ted all  that  he  has  found,  in  the  mechanism  of  the  human 
body ; but  the  living  power  which  compensates  for  the  want 
of  levers,  which  allows  every  where  power  to  be  sacrificed  to 
the  beauty  of  form,  which  has  strength  in  convulsive  and 
violent  actions,  to  break  the  very  bones;  this  is  the  act  of  In- 
finite Wisdom,  on  which  our  admiration  should  chiefly  dwell. 


277 


OF  THE  TENDONS,  LIOAMENTS,  &C. 

It  is  but  the  very  elements  of  so  deep  a subject  that  can  be 
delivered  here.  I must  proceed  to  explain  those  provisions 
for  easy  motion,  which  may  be  considered  as  belonging  to  the 
muscles  and  bones,  and  as  preparing  us  for  a knowledge  of 
the  joints. 


CHAP.  X. 

OF  THE  TENDONS,  LIGAMENTS,  BURSjE,  AND  ALL  THE  PARTS 
WHICH  BELONG  TO  THE  BONES  OR  MUSCLES,  OR  WHICH 
ENTER  INTO  THE  CONSTITUTION  OF  A JOINT. 

The  bones  and  muscles  themselves  are  but  the  smallest 
part  of  that  beautiful  mechanism  by  which  the  motions  of  the 
human  body  are  performed  ; for  the  parts  by  which  the  bones 
are  joined  to  each  other,  or  the  muscles  fixed  into  the  bones, 
are  so  changed,  and  varied  in  their  forms,  according  to  the 
uses  of  each  part,  as  to  give  a natural  and  easy  shape  to  the 
limbs,  security  and  firmness  to  their  motions,  and  lubricity  and 
smoothness  to  the  joints  by  w'hich  these  motions  are  perform- 
ed ; and  this  apparatus  deserves  our  attention,  not  merely  that 
we  may  know  the  forms  of  these  joinings,  but  that  we  may 
learn  something  of  the  nature  and  uses  of  each  part,  and  the 
various  degrees  of  sensibility  with  which  each  is  endowed ; 
for,  from  this  kind  of  study  conclusions  will  arise,  which  may 
lead  us  to  the  knowledge  of  their  diseases,  suggesting  the 
means  of  their  prevention  and  cure. 

There  is  a difference  in  the  parts  of  the  human  body,  ac- 
cording to  the  several  uses  for  which  they  are  designed  ; some 
are  vascular  and  soft,  others  bony  and  hard ; some  sensible, 
and  very  prone  to  inflammation  and  disease,  others  callous 
and  insensible,  having  little  action  in  their  natural  state,  and 
little  proneness  to  disease. — The  greater  part  of  the  human 
body  is  merely  inanimate  matter,  united  into  a moving  and 
perfect  whole  by  the  system  of  the  nerves  which  abound  in 
each  creature,  according  to  its  wants,  and  are  distributed  in 
each  system  according  to  the  uses  and  functions  of  every  part. 
In  some  places  there  is  such  a conflux  of  nerves,  as  form  the 
most  delicate  and  perfect  sense,  endowing  that  part  with  the 
fullest  life  ; while  others  are  left  without  nerves,  almost  inani- 


278 


OP  THE  TENDONS, 

mate  and  dead,  lest  feeling,  where  it  ought  not  to  be,  should 
derange  the  whole  system. 

The  living  parts  of  the  system  are  the  muscles  and  nerves  j 
the  muscles  to  move  the  body,  and  perform  its  offices,  each 
muscle  answering  to  its  particular  stimuli,  and  most  of  them 
obeying  the  commands  of  the  will;  the  nerves  to  feel,  to  suf- 
fer, and  to  enjoy,  to  issue  the  commands  of  the  will,  and  to 
move  the  muscles  to  action  : but  still  the  muscles  have  their 
own  peculiar  kind  of  life,  superior  to  the  nerves,  and  indepen- 
dent of  them,  always  acting,  always  capable  of  greater  action, 
always  ready  to  receive  the  impulse  of  the  nerves.  It  is  a 
power  which  survives  that  of  the  nerves,  acting  even  when 
severed  from  the  general  system ; and  acting  often  on  the 
living  body,  without  the  impulse  of  the  nervps,  and  sometimes 
in  opposition  to  the  will.  The  dead  matter  of  the  system* 
joins  these  living  parts,  and  performs  for  them  every  subservi- 
ent office,  forms  coverings  for  the  brain,  coats  for  the  nerves, 
sheaths  for  the  muscles  and  tendons,  ligaments  and  bursse,  and 
all  the  ap]oaratus  for  the  joints  ; unites  them  into  one  whole  by 
a continued  tissue  of  cellular  substance,  which,  from  part  to 
part  through  all  its  various  forms,  has  no  interruption,  and  suf- 
fers no  change,  but  still  preserves  its  own  inanimate  nature, 
while  it  joins  the  living  parts  to  each  other.  The  tendons,  liga- 
ments, periosteum,  and  bursae,  are  all  composed  of  this  cel- 
lular substance,  which,  by  its  elasticity,  binds  and  connects  the 
parts,  and,  by  its  dead  and  insensible  nature,  is  less  exposed  to 
disease,  and  is  a fitter  medium  of  connection  for  the  living 
system. 


OF  THE  FORMS  OF  THE  CELLULAR  SUBSTANCE. 

Under  various  modifications  and  shapes,  the  cellular  sub- 
stance performs  most  important  offices  among  the  living  parts  : 
1.  It  forms  CELLS  over  all  the  body,  which  allow  the  parts 
to  glide  and  move  easily,  which  contain  the  fluid  that  makes 
all  the  motion  of  parts  more  easy  and  free,  which  store  up  fat 
to  fill  the  interstices,  to  support  the  parts  in  their  action,  to 
give  a plumpness  to  all  the  body,  and  to  be  re-absorbed  for 
the  needs  and  uses  of  the  system.  This  cellular  substance  is 
peculiarly  useful  to  the  muscles,  dives  in  among  them,  keeps 
their  fibres  at  sucb  due  distance,  that  each  may  have  its  action, 
supports  and  lubricates  them ; so  that  perhaps  the  difference 

* This  expression  of  the  dead  matter  of  the  system  must  only  be  considered  as  a relative 
term,  for  these  parts  are  not  dead  nor  insensible,  although  their  sensibility  be  ordered  witl) 
aucli  a relation  to  their  office,  as  not  to  obstruct  the  play  and  motion  of  the  limbs.  C.  B 


279 


LIGAMENTS,  BURS^,  &C. 

of  strength,  in  health  and  disease,  depends,  at  least,  in  some 
degree,  upon  this  support.  The  thinner  halitus  makes  the 
play  of  the  fibres  easy  and  free ; and  the  fat  not  only  supports 
the  fibres  in  their  action,  but  lubricates  them  so,  that  a want 
of  it  is  painful,  while  a superabundance  of  it  encumbers  the 
body.  And  Haller  seems  to  have  believed,  that  a diseased  in- 
crease of  it  might  not  only  oppress,  but  almost  annihilate  the 
muscular  fibre. 

2.  But  it  is  still  further  essential  to  a muscle,  that  while  it 
moves,  it  should  neither  be  hurt  itself,  nor  harm  the  surround- 
ing parts.  Therefore,  where  one  muscle  moves  over  another 
muscle,  soft  flesh  upon  soft  flesh  like  itself,  there  can  be  no 
hurtful  friction,  and  the  cellular  substance  is  loese  and  natural, 
preserving  its  common  form.  But  where  tendons  rub  upon 
tendons,  or  bones  upon  bones,  or  where  tendons  rub  upon 
muscles,  or  upon  each  other,  some  defence  is  needed,  and  the 
cellular  substance  assumes  a new  form.  The  cells  are  run  to- 
gether into  one  large  cell,  with  thicker  coats,  and  a more  copi- 
ous exudation,  so  that,  being  more  liberally  bedewed  with  a 
gelatinous  mucus,  it  prevents  the  bad  effects  of  friction,  and  is 
called  a bursa  mucosa,  or  mucous  bag.  These  mucous  bags 
are  placed  under  rubbing  tendons,  and  chiefly  about  the  great- 
er joints;  some  are  large,  and  othei-s  small ; their  glairy  liquor 
is  the  same  with  that  which  bedews  the  cellular  substance,  or 
the  cavities  of  the  joints ; and  the  provision  of  nature  is  so 
perfect,  that  the  occasions  which  require  bursa;  seem  to  form 
them  by  friction,  out  of  the  common  cellular  substance. 

3.  It  is  often  useful  that  an  individual  muscle  should  be  en- 
closed in  a tendinous  sheath,  to  give  it  strength  and  firmness, 
and  to  preserve  it  in  its  shape,  or  to  direct  its  force.  All  mus- 
cles, or  almost  all  muscles,  form  for  themselves  individual 
sheaths,  such  as  are  seen  enclosing  the  supra-spinatus  and  infra- 
spinatus of  the  scapula,  the  biceps  humeri,  and  most  of  the 
muscles  of  the  leg  and  thigh ; but  it  is  especially  necessary 
that  the  whole  muscles  of  the  limb  should  be  enclosed  in  some 
stronger  membrane  than  the  common  skin,  both  to  give  form 
to  the  limb,  and  strength  to  its  muscles,  and  to  keep  the  indi- 
vidual muscles  in  their  proper  places,  which  otherwise  might 
be  luxated  and  displaced.  And  so  the  trunk  of  the  body,  the 
arm,  the  thigh,  the  leg,  are  bound  each  with  a strong,  smooth, 
and  glistening  sheath,  formed  out  of  the  cellular  substance, 
condensed  and  thickened  by  continual  pressure.  And  this 
also  is  thicker  and  stronger,  according  to  the  need  that  there 
may  be  for  such  a help  ; for  it  is  weaker  over  the  flat  muscles 
of  the  back,  or  of  the  abdomen,  stronger  en  the  arm,  stronger 
still  over  the  strong  muscles  of  the  thigh.  It  is  hardly  to  be 


280 


OF  THE  TENDONS, 

distinguished  in  the  child ; grows  thicker  and  stronger  as  we 
advance  in  years  and  in  strength,  and  in  the  arms  of  workmen 
it  grows  particularly  thick  and  strong,  encreasing  in  the  back, 
shoulder  or  limbs,  according  to  the  particular  kind  of  labour. 
These  are  the  membranes,  which,  by  enclosing  the  muscles 
like  sheaths,  are  called  the  vagina,  or  fascia  of  the  arm,  the 
leg,  the  thigh,  &c. 

4.  Tendons  or  ropes  were  needed,  for  the  muscles  could 
not  be  implanted  thick  and  fleshy  into  each  bone,  without  a 
deformity  of  the  limbs,  and  especially  of  the  joints,  which 
would  have  been  not  unshapely  only,  but  which  must  have 
abridged  them  of  their  motions  and  uses.  Where  a muscle  is 
not  implanted  directly  into  a bone,  tendons  are  seldom  required ; 
and  so  there  are  no  tendons  in  the  heart,  the  tongue,  the  oeso- 
phagus, the  stomach,  intestines,  or  bladder.  But  where  ten- 
dons pass  over  bones,  or  traverse  the  joints,  their  force  is  con- 
centrated into  narrower  bounds ; and  long  tendons  are  fixed 
to  the  ends  of  the  muscles,  to  pull  the  bones.  These  tendons 
were  once  believed  to  be  but  the  collected  fibres  of  muscles, 
gathered  into  a more  condensed  form ; by  which  condensa- 
tion, their  properties  of  feeling  and  motion  were  lost,  while 
they  became  hard,  white,  and  glistening  ; and  it  was  believed, 
that  parts  which  were  fleshy  in  the  child,  became  tendinous  in 
the  adult.  But  we  know  by  the  microscope,  that  the  tendon 
is  not  truly  continued  from  the  flesh ; that  the  fibres  of  the 
tendon,  and  of  the  flesh,  are  not  in  the  same  line,  the  fibres  of 
all  penniform  muscles  running  into  their  tendon,  in  a direction 
more  or  less  oblique ; and  good  anatomists  have  been  able  to 
separate  the  tendon  from  the  flesh,  without  any  violence,  and 
Avith  the  bluntest  knives. — Muscles  are  irritable,  and  have 
nerves ; tendons  are  quit  dead,  have  no  visible  nerves,  have 
neither  feeling  nor  motion,  nor  any  endowment  by  which  we 
should  believe  them  to  be  allied  to  the  living  parts  of  the  sys- 
tem ; and  many  tendons,  as  the  expansion  of  the  palmaris, 
may  be  unravelled  into  mere  cellular  substance.* 

5.  The  PERIOSTEUM  is  merely  a condensation  of  the  com- 
mon cellular  substance,  formed  in  successive  layers  : and  the 
tendons  are  of  the  substance  of  the  periosteum  ; they  mix  with 
the  periosteum,  and  are  implanted  into  it.  In  dissecting  a 
child,  we  tear  up  the  periosteum  along  with  tendons  and  with- 
out hurting  the  bones ; but  in  process  of  time,  the  periosteum., 
and  consequently  the  tendons,  are  inseparably  fixed  to  the 
bones.  The  periosteum,  tendons,  fasciae,  and  burs®  mucosae, 

* Tlie  tendons  are  the  continuation  of  the  interaticial  cellular  membrane  of  tlie  muscle; 
and  1 have  succeeded  in  unravelling  them  into  a web.  C.  B. 


281 


LIGAMENTS,  BURS^,  &C. 

are  all  of  one  substance,  and  of  one  common  nature  ; they  are 
various  modifications  of  that  dead  matter,  which  having  but 
little  vascularity,  and  no  feeling,  and  hardly  any  disposition  to 
disease,  is  the  fittest  for  its  office,  and  bears  the  roughest  usage 
in  our  experiments,  and  the  most  violent  shocks  in  the  mo- 
tions of  the  body,  without  any  signs  of  feeling,  and  without 
falling  into  disease. 

6.  These  tendons  must  be  bound  firmly  down,  for  if  they 
were  to  rise  from  the  bones,  during  the  actions  of  the  muscles 
to  which  they  belong,  the  effect  of  contraction  would  be  lost, 
and  they  would  disorder  the  joint,  starting  out  in  a straight  line 
from  bone  to  bone,  like  a bow-string  over  the  arch  of  a how. 
The  same  inanimate  substance  still  perfortns  this  office  also  ; 
for  the  tendons  of  one  muscle  often  split  to  form  a sheath  or 
ring  for  the  next,  or  their  tendons,  after  taking  hold  of  the 
bone,  spread  their  expansion  out  over  all  the  bone,  so  as  to 
form  an  entire  sheath  for  the  finger  and  toe ; or  there  is  a wide 
groove  in  the  bone  which  receives  the  tendons,  and  it  is  lined 
with  a cartilage,  and  with  a lubricated  membrane  ; the  mem- 
brane comes  off  from,  the  lips  of  the  groove,  or  from  corners 
or  edges  of  the  bone,  passes  over  the  tendons,  so  as  to  form  a 
bridge,  or  often  it  forms  a longer  sheath,  as  in  the  fingers,  or 
where  the  peronaei  muscles  pass  behind  tbe  ancle,  and  thus  the 
VAGINA  or  SHK  '.THS  of  the  TENDONS  are  connected  with  the  ten- 
dons, periosteum,  and  other  modifications  of  the  common  cel- 
lular membrane. 

7.  The  periosteum  which  has  run  along  one.bone,  leaves  it 
at  the  head,  and,  forming  a bag  for  the  joint,  goes  onwards 
to  the  next  bone.  Thus,  the  periosteum  of  all  the  bones  is 
one  continued  membrane,  passing  from  point  to  point ; each 
bone  is  tied  to  tbe  next  by  its  own  periosteum,  and  this  mem- 
brane, betwixt  the  end  of  one  bone  and  the  beginning  of  the 
next,  is  so  thickened  into  a strong  and  hard  bag,  as  to  form  the 
capsule  of  the  joint ; and  the  periosteum  is  assisted  in  perform- 
ing this  office,  by  the  tendons,  fasciae,  bursae,  and  all  that 
confusion  of  cellular  substance  which  surrounds  the  joint.  The 
CAPSULE  of  the  JOINT  is  then  a firm  and  thick  bag,  which,  like 
a ligamenf,  binds  the  bones  together,  keeps  their  heads  and 
processes  in  their  right  places,  contains  that  glairy  liquor  with 
which  the  heads  of  moving  bones  are  bedewed,  and  prei'ents 
the  adjacent  parts  falling  inwards,  or  being  catched  betwixt 
the  bones  in  the  bendings  of  the  joints.  The  capsule  of  every 
joint  proceeds  from  the  periosteum,  and  is  strengthened  by 
the  tendons;  it  is  formed  like  these  parts,  out  of  the  cellular 
membrane;  and  when  a bone  is  broken,  or  its  periosteum 
destroyed  by  any  accident  or  disease,  when  a tendon  snap« 

VOL.  i.  N n 


282 


OF  THE  TENDONS, 

across,  Avhen  a joint  is  luxated,  and  the  capsule  torn,  the  in- 
jury is  soon  repaired  by  a thickening  of  the  cellular  substance 
round  the  breach  ; and  wherever  a bone  being  luxated,  is  left 
unreduced,  a new  socket,  new  periosteum,  new  ligaments, 
and  new  bursae,  are  formed  out  of  the  common  cellular  sub- 
stan<  e : and  though  the  tendons  may  have  been  torn  away 
from  the  head  of  the  bone,  they  are  fixed  again,  taking  a new 
hold  upon  the  bone. 

8.  There  are  other  ligaments  of  a joint  which  prevent  its 
luxation,  guarding  it  at  its  sides,  or  round  ail  its  circle,  accord- 
ing to  its  degree  of  motion ; and  those  ligaments  are  of  the 
same  nature  with  the  first,  or  bursal  ligaments  arise  like  them, 
from  the  periosteum  chiefly,  or  indeed  are  truly  but  a thicken- 
ing of  the  bursal  ligament  at  certain  points. 

The  universal  connection  of  these  parts  is  now  sufficiently 
explained,  since  we  have  followed  the  several  forms  of  cellular 
substance;  1st,  Clothing  the  bones  with  a thick  membrane, 
which,  though  insensible,  and  almost  inanimate  in  its  own  na- 
ture, conveys  blood  vessels,  the  means  of  life,  to  the  bones,  and 
is  named  periosteum  : 2dly,  The  same  periosteum,  thickened 
and  strengthed  by  the  adhesion  of  surrounding  parts,  so  as  to 
form  the  capsules  for  the  joints  : 3dly,  The  tenden  also  con- 
tinued from  the  periosteum,  and  not  growing  from  the  muscle, 
but  merely  joined  to  it:  4thly,  We  see  that  smaller  tendon, 
expanded  into  a thinner  tendinous  sheet,  as  in  the  braivn  of  the 
leg  where  the  ham-strings  (whose  expansion  strengthens  the 
the  knee-joint)  go  down  over  the  muscles  of  the  leg : 5thly, 
We  see  the  perpendicular  partitions  of  this  fascia  going  down 
among  the  muscles,  and  dividing  them  from  each  other;  and 
the  cellular  substance  which  lies  under  the  fascia,  and  imme- 
diately surrounds  the  muscle,  cannot  be  distinguished  from  the 
inner  surface  of  the  fascia  itself : 6thly,  And  as  for  the  burss, 
we  see  that  they  are  formed  wherever  the  tendon  rubs  over  a 
bone.  The  upper  surface  of  the  bursa  is  formed  by  the  ten- 
don which  rubs  over  the  bone  : the  lower  surface  of  the  same 
bursa  is  formed  by  the  periosteum  of  the  bone  which  it  de- 
fends : the  sides  are  formed  by  the  common  cellular  substance. 
Its  cavity  appears  to  be  merely  an  enlarged  cell : and  the 
bursae  mucosae  and  capsular  ligaments  are  plainly  of  one  and 
the  same  nature:  their  liquors  are  the  same,  they  often  open 
into  one  another  naturally,  or  if  not  naturally,  at  least  it  is  ne 
disease,  since  no  bad  effects  ensue. 

I must  now  explain  more  fully  the  constitution  and  nature  of 
all  the  less  feeling  parts  : for  what  I have  said  might  be  thought 
to  imply  absolute  insensibility  and  total  exemption  from  dis- 
ease or  pain  : whereas  the  sensibility  of  tendons,  ligament?, 


283 


LIGAMENTS,  BURS^,  &C. 

faursse,  and  joints,-  stands  on  the  same  footing  with  the  feeling 
of  bones  : they  are  insensible  in  health;  not  easily  injured; 
entering  slowly  into  disease ; but  their  diseases  are  equally 
dreadful  from  their  duration  and  from  their  pain  : for  by  in- 
flammation, their  organization  is  deranged,  their  healthy  con- 
sistence destroyed,  and  their  sensibility  excited  in  a dreadful 
degree. 

The  tendons  of  animals  have  been  cut  or  pierced  with 
erabowelling  needles  ; they  have  been  pinched  with  nippers, 
and  torn  and  cauterized  ; they  have  been  burnt  with  a lighted 
stick,  while  the  creature  neither  struggled  nor  shrunk  from  the 
irritation,  nor  ever  gave  the  smallest  sign  of  pain.  Oil  of  vitriol 
has  been  poured  upon  each  of  the  parts  belonging  to  a joint, 
and  a piece  of  caustic  has  been  dropped  into  its  cavity,  but  still 
no  pain  ensued ; nay,  some  have  been  so  bold,  may  I not  say 
so  vicious,  as  to  repeat  these  experiments  upon  the  human 
body,  pinching,  pricking,  and  burning  the  tendons  of  the  leg, 
and  piercing  them  with  knives,  in  a poor  man,  whose  condi- 
tion did  not  exempt  him  fiom  this  hard  treatment;  who  was 
ignorant  of  this  injustice  that  was  done  to  him,  whtle  his  cure 
was  protracted,  and  he  was  made  a spectacle  for  a whole  city. 
Without  such  cruel  and  inhuman  practices  we  do  not  want 
oppqrtunities  of  knowing,  that,  in  the  human  body  also,  the 
tendons  and  bursas  have  no  acute  feeling.  When  we  cut  open  a 
fascia  or  tendinous  membrane,  there  is  little  pain  : when  (as  in 
amputation)  we  cut  the  ragged  tendons  even  and  neat,  there  is 
no  pain  : when  we  snip  with  our  scissars  the  ragged  tendons  of 
a bruised  finger  to  cut  it  off,  the  patient  does  not  feel : when 
we  see  tendons  of  suppurating  fingers  lying  flat  in  their  sheaths, 
we  draw  them  out.  with  our  forceps,  or  touch  them  with  probes 
^ without  exciting  pain.  In  the  old  practice  of  sevving  tendons, 
there  was  some  danger,  but  no  immediate  pain  : when  we 
cut  down  into  the  cavity  of  a joint,  still  the  pain  is  but  slight. 
In  a luxation,  there  is  comparatively  little  pain.*  There  is  no 
pain  when  the  ligament  of  the  patella  is  broken  away  from 
the  tibia,  nor  when  the  great  Achillis  tendon  is  torn.  There 
is  but  little  pain  in  the  moments  of  those  accidents  which  ap- 
pear slight  in  the  time,  but  which  turn  out  to  be  the  most 
dreadful  sprains.  Yet,  after  rupture  of  the  patella,  the  knee 
inflames  and  swells : after  rupture  of  the  Achillis  tendon, 

* I cannot  let  tliis  pass  without  again  entering  a protest.  The  pain  of  a dislocation  is  ex- 
cessive. It  is  the  greatest  which  tlie  ingenuity  of  man  has  invented  as  a torture,  and  so  it 
is  incorr^t  to  say,  as  above,  that  tendons  have  been  pinched  and  torn  without  giving  pain. 

, In  the  joints  the_  parts  are  endowed  with  a sensibility  well  adapted  to  be  a check  on  undue 
exertion,  adinonisliing  us  of  that  degree  of  violence  which  would  be  injurious  to  tlir 
structure.  Yet  tuey  are  certainly  not  sensible  like  the  other  parts  of  tlie  frame,  and  verv 
happily  so,  as  then  we  could  neither  sit,  stand,  nor  walk. 


OF  THE  TENDONS, 


28’4i 

there  is  swelling  and  inflamation,  with  such  adhesion  of  the 
parts  as  makes  the  patient  lame  ; after  the  slightest  sprain,  i 
such  inflammation  sometimes  comes  on  as  destroys  the  joint. 
There  is  but  little  pain  when  we  first  make  an  opening  into  any 
joint ; yet  it  often  brings  on  such  pain  and  fever,  that  the 
patient  dies.  In  short,  every  thing  conspires  to  prove;  that  ! 
though  in  wounds  of  the  less  feeling  parts,  there  is  indeed 
future  danger,  there  is  no  immediate  pain.  Still  there  are 
many  accidents  which  prove  to  us,  that  even  in  health,  the  [ 
joints  are  not  entirely  exempted  from  pain  : a smart  stroke  on 
the  knuckles,  or  a blow  on  the  elbow,  or  a fall  upon  the  knee, 
are  not  perhaps  the  purest  instances  of  feeling  in  joints ; for 
such  blow  may  have  hurt  some  external  nerve ; but  when  a 
small  moveable  cartilage  forms  within  the  joint  of  tlie  knee, 
though  it  be  small  and  very  smooth,  and  lodged  fairly  within 
the  cavity  of  the  joint,  it  often  gets  betwixt  the  bones,  causing 
instant  lameness ; the  moment  it  causes  this  lameness,  it 
brings  dreadful  pains : the  pain,  the  lameness,  and  all  the 
feeling  of  inconveniency  subside  the  instant  that  this  cartilage 
is  moved  away  from  betwixt  the  bones  ; and  the  joint  con- 
tinues easy  till  this  moving  cartilage  chances  again  to  fall  in 
betwixt  the  heads  of  the  bones.  Even  the  pain  from  a blow 
upon  the  knee,  for  example,  is  plainly  within  the  joint,  and  is 
caused  by  the  force  with  which  the  patella  is  struck  Sown 
against  the  ends  of  the  bones.  What  indeed  is  a sprain,  but  a 
general  violence  and  twisting  of  all  the  parts  which  compose 
the  joint  ? These  parts  are  of  one  common  nature,  and  may 
be  arranged  and  enumerated  thus  : a joint  is  composed  of  the 
heads  of  the  bones  swelling  out  into  a broader  articulating 
surface,  and  of  a thin  plate  of  cartilage,  which  covers  and 
defends  the  head  of  each  bone : sometimes  of  small  and 
moveable  cartilages  which  roll  upon  the  bones,  and  follow  all 
the  motions  of  the  joint,  and,  like  friction  wheels  in  machines  .w|j 
of  human  invention,  abate  the  bad  effects  of  motion.  There 
are  mucous  glands,  or  rather  mucous  bags,  which  convey  a 
lubricating  fluid  : and  there  is  a bursal  ligament  which  forms 
the  purse  of  the  joint,  binds  the  bones  together,  contains  the 
synovia,  and  prevents  the  surrounding  parts  from  being  catched  [ 
in  the  joint:  there  are  lesser  ligaments  on  the  outside  of  this,  ' 
going  along  the  sides  of  the  joint,  and  passing  from  point  to 
point : there  are  great  tendons  moving  over  the  joint,  and 
bursae,  or  raucous  bags,  which  accompany  these  tendons,  and  i 
prevent  the  violence  which  their  continual  rubbing  might  do 
to  the  bones.  All  these  parts  are  of  one  constitution  and  na- 
ture ; we  cannot  say  that  they  are  insensible,  for  their  feeling 
is  only  deferred;  it  is  slow,  but  not  the  less  severe.  The  eye 


LIGAMENTS,  BURS^,  &.C.  285 

feels  the  instant  that  a mote  falls  upon  it ; but  the  skin  does 
not  feel  a blister  till  it  has  been  some  hours  applied  ; the  liga- 
ments and  joints  feel  still  less  in  the  instant  that  any  injury  is 
done  : but  as  the  inflammation  of  the  blister  excites  the  feel- 
ing, and  destroys  the  fabric  of  the  skin,  producing  pain  and 
derangement  of  its  parts,  the  inflammation  of  joints,  and  of  all 
the  parts  belonging  to  them,  breaks  up  the  organization  of  the 
part,  evolves  the  feeling,  *and  then  in  them  also  comes  disease 
and  violent  pain.  They  are  slow  in  entering  into  action,  hut 
once  excited,  they  continue  to  act  with  a perseverance  quite 
unknown  in  any  other  part  of  the  system.  Their  mode  of 
action,  whatever  it  may  be  at  the  time,  is  not  easily  changed  : 
if  at  rest,  they  are  not  easily  moved  to  action,  and  their  ex- 
cessive action  once  begun  is  not  easily  allayed.  The  diseases 
are  infinite  to  which  these  parts  are  subject.  They  are  sub- 
ject to  dropsical  elfusions ; they  are  subject  to  gelatinous  con- 
cretions ; they  are  subject  to  slight  inflammation,  to  suppura- 
tion. to  erosions  of  their  cartilages,  and  to  exfoliation,  of  their 
bones,  corresponding  with  the  dropsies,  suppurations,  and  mor- 
tifications of  the  softer  and  more  feeling  parts.  Rheumatism 
is  an  inflammation  round  the  joints,  with  a slighter  effusion, 
which  is  soon  absorbed  : chronic  rheumatism  is  a tedious  and 
slow  inflammation,  with  gelatinous  effusions  round  the  tendons, 
and  permanent  swelling  and  lameness  of  the  joints.  Gout,  in 
a joint,  is  a high  inflammation,  with  a secretion  of  earthy  mat- 
ter into  its  cavity.  The  inflammation  of  tendons  is  sprain  : 
effusion  of  gelatinous  matter  round  them  is  ganglion:  suppura- 
tions in  the  tendinous  sheaths  is  whitloe : the  inflammation 
tion  of  bursae  is  false  white  swelling,  not  easily  distinguished 
from  the  true  : the  disease  of  the  joint  itself  is  either  a dropsy, 
where  the  joint,  though  emptied  by  the  lancet,  is  filled  up  again 
in  a few  hours,  showing,  how  continual,  and  how  profuse,  both 
the  exhalation  and  absorption  of  joints  naturally  is : or  it  is 
white  swelling,  which,  next  to  consumption,  is  the  most  dread- 
ful of  all  scrophulous  diseases,  which  begins  by  inflammation 
in  the  joint  itself,  is  marked  by  stiffness,  weakness,  loss  of  mo- 
tion, and  pain : which  goes  on  through  all  the  stages  of  high 
inflammation,  dreadful  pain,  destruction  of  cartilages,  enlarge- 
ment of  bones,  suppurations  and  spontaneous  openings  of  the 
joints  j which  sometimes  stops  by  an  effusion  of  callus  and  con- 
cretion of  the  bones,  forming  a stilf  joint,  but  which  oftener 
ends  in  hectic  fever,  diarrhoea,  morning  sweats,  and  extreme 
weakness^  so  that  the  patient  dies,  exliausted  with  fever  and 
pain. 


BOOK  III. 


OF  THE  JOINTS. 


CHAP.  1. 

JOINTS  OF  THE  HEAD  AND  TRUNK. 

JOINTS  OF  THE  HEAD  AND  SPINE. 

At  (MOST  every  tiling  relating  to  the  beads  and  processes 
of  the  bones,  and  every  proposition  concerning  the  motions 
which  they  have  to  perform,  has  been  already  explained,  anti- 
cipating much  of  the  <^natomy  of  the  joints  : and  the  principles 
of  motion  mentioned  in  describing  the  bones,  shall  form  the 
chief  propositions  on  which  my  descriptions  of  joints  shall  be 
arranged,  seeking  that  method  chiefly  by  which  the  joints  may 
be  easily  and  rapidly  explained  ; for  it  is  a subject  on  which 
volumes  might  be  bestowed,  and  not  in  vain. 

VVe  may  compare,  in  the  following  order,  the  chief  motions 
of  the  head  and  trunk.  The  head  is  so  placed  upon  the 
oblique  surfaces  of  the  atlas,  that  it  cannot  turn  in  circles ; but 
at  that  joint  all  the  nodding  motions  are  performed.  The  atlas 
rests  so  upon  the  dentatus,  that  there  all  the  turning  motions 
are  performed.  The  neck  and  loins  have  their  vertebral  so 
loosely  framed,  with  such  perpendicular  processes  and  easy 
joints,  that  there  all  the  bending  motions  are  performed,  while 
the  back  is  fixed,  or  almost  fixed,  by  its  connection  with  the  ribs 
and  by  the  obliquity  and  length  of  its  spines ; and  though, 
upon  the  whole,  the  spine  turns  many  degrees,  yet  it  is  with 
a limited  and  elastic  motion  where  the  whole  turning  is  great, 
but  the  movement  of  each  individual  bone  is  small. 

To  secure  these  motions,  we  find,  1.  The  occipital  condyles 
received  into  hollows  of  the  atlas,  where  the  oblique  position 
of  the  condyles  secures  the  joint,  the  occipital  condyles  look- 
ing outwards,  the  articulating  surfaces  of  the  atlas  looking  to- 
wards each  other,  the  occiput  set  down  betwixt  them,  so  as  to 
he  secured  towards  either  side,  and  the  obliquity  of  the  joint 


JOINTS  OF  THE  HEAD  AND  SPINE,. 


287 


being  such  withal  as  to  prevent  the  head  from  turning  round. 
These  joints  of  the  occiput  with  the  atlas,  are,  like  the  greater 
joints  of  the  body,  secured  with  regular  capsules,  or  bag-like 
ligaments  for  each  condyle,  each  rising  from  a rough  surface 
on  the  vertebrae,  and  being  fixed  into  a roughness  at  the  root 
of  the  condyle.  2.  VVe  find  a flat  membranous  ligament,  which 
extends  from  the  ring  of  the  atlas  to  the  ring  of  the  occipital  hole, 
closing  the  interstice  betwixt  the  occiput  and  the  atlas  : it  is 
confounded  at  the  sides  with  the  capsules  of  the  articulating 
processes ; is  very  strong  before ; and  at  the  middle  short 
point  of  the  atlas  it  seems  a distinct  ligament,  which  is 
strong  only  at  this  point,  and  very  lax  and  membranous 
behind.*  3.  We  find  the  atlas  tied  to  the  dentatus,  by  a more 
complete  order  of  ligaments.  These  are,  1st,  (as  betwixt  the 
atlas  and  dentatus,)  regular  capsules,  or  bags,  fixing  the  con- 
dyles of  one  vertebrae  to  the  condyles  of  the  other.  2dly.  A 
cross  ligamentf  which,  crossing  the  ring  of  the  first  vertebrfe, 
makes  a bridge,  embraces  the  neck  of  the  tooth-like  process, 
and  ties  it  down  in  its  place.  3dly,  A smooth  and  cartilaginous 
surface  all  round  the  root  of  the  tooth-like  process,  where  this 
tooth  of  the  dentatus  turns  in  the  ring  of  the  atlas,  and  is  bound, 
by  the  ligament ; and  this  rolling  of  the  atlas  upon  the  axis  of  the 
dentatus  is  so  fair  and  proper  a joint,  that  it  also  is  all  included 
in  a capsular  ligament.  4thly,  The  point  of  the  tooth-like 
process  having  threaded  the  ring  of  the  atlas,  almost  touches 
the  occipital  hole  ; and  there  another  ligament  ties  it  by  its 
point  to  the  occipital  hole.J 

All  the  other  vertebrae  have  another  kind  of  articulation  : 
to  which  the  occiput,  atlas,  and  dentatus  are  the  only  excep- 
tions, for  their  motions  are  particular,  and  quite  different  from 
the  rest.  The  atlas  and  dentatus  bend,  turn  and  roll  by  con- 
nections resembling  the  common  joints  of  the  body;  but  the 
other  vertebrae  are  united,  each  by  its  intervertebjial  sub- 
stance, to  the  bones  above  and  below ; they  are  also  united 
by  their  articulating  processes  to  each  other  : each  articulating 
process  is  held  to  another  by  a distinct  capsule ; each  inter- 

* Tbi9  is  part  of  what  Winslow  called  lioamentum  infusdibiliforme,  a FuxfiEL-LiKE 
HGAMENT,  joining  the  first  vertebrae  to  the  occiput. 

f Viz.  Ligamentum  transversale,  or  transverscm  ; and  what  are  called  the 
APPENDICES  of  the  transverse  ligament,  are  merely  its  edges,  extending  upwards  and 
downwards,  to  be  fixed  into  the  dentatus,  and  into  the  occipital  hole,  so  as  to  enclose  the 
tooth-like  process  of  the  dentatus  in  a capsule. 

; There  are  two  flat  ligaments  which  come  from  about  the  neck  or  root  of  tlie  tooth-lilce 
process,  and  which  m obliquely  upwards,  to  be  fixed  into  the  groove  just  behind  the  lip  of 
the  occipital  hole ; but  the  ligament  from  the  point  of  the  tooth-like  process  is  not  what  it  has 
been  supposed,  a lair  round  ligament  of  some  strength  ; there  is  nothing  more  than  a few 
straggling  fibres  of  ligament  going  from  the  point  to  the  occiput,  though  Enstachius  has  drawn 
it  round  and  strong. 


288 


JOINTS  OF  THE  HEAD  AND  SPINE. 


vertebral  substance  is  secured,  bound  down,  and  strengthened 
by  strong  ligaments ; for  the  intervertebral  substance,  which  of 
itself  adheres  very  strongly  to  the  periosteum,  and  to  the  rough 
socket-like  surface  upon  the  body  of  each  vertebra,  is  further 
secured  by  a sort  of  cross  ligament,  which  go  from  the  rim  or 
edge  of  one  vertebra  to  the  edge  of  the  next,  over  the  inter- 
vene oral  substance;  and  so,  by  adhering  to  the  intervertebral 
substance,  they  strengthen  it.  These  ligaments  cross  each 
ol  icr  over  the  interstice  betwixt  each  vertebra,  and  are  very 
strung.  They  are  very  regular,  beautiful,  and  shining,  and  are 
named  intervertebral  ligaments. 

The  spine  is  further  secured  by  a general  ligamentous  or 
tendinous  expansion,  which  goes  over  the  foreparts  of  all  the 
vertebrae,  from  top  to  bottom  of  the  spine.  It  begins  at  the 
forepart  of  the  atlas;  it  almost  passes  the  body  of  the  denta- 
tus,  or  is  but  very  slightly  attached  to  it.  It  is  at  first  pointed, 
small,  and  round ; it  begins  to  expand  upon  the  third  verte- 
bra of  the  neck,  so  as  to  cover  almost  all  its  body.  It  goes 
down  along  the  bones,  chiefly  on  their  foreparts,  and  is  but  little 
observed  on  their  sid^s.  • It  is  weaker  in  the  neck,  where  there 
is  much  motion : stronger  in  the  back,  where  there  is  none ; 
weaker  again  in  the  loins,  where  the  vertebrae  move  ; but  still 
on  the  bodies  of  all  the  vertebrae  it  is  seen  white,  shining,  and 
tendinous.  We  can  distinguish  all  along  the  spine  interrup- 
tions and  fasciculi,  or  firmer  bundles  going  from  piece  to  piece 
of  the  spine  ; which  fasciculi  are  indeed  very  seldom  continued 
without  interruption,  further  than  the  length  of  two  or  three 
vertebras ; yet  the  whole  is  so  much  continued,  that  it  is  consi- 
dered as  one  uninterrupted  sheath,  and  is  called  the  external 

or  ANTERIOR  VAGINA,  Or  LIGAMENT  of  the  SPINE. ^ 

But  still  the  canal  of  the  spine  were  left  open  and  undefend- 
ed, rough  and  dangerous  to  the  spinal  marrow,  if  internal  liga- 
ments were  not  added  to  these.  The  rings  of  the  vertebrae 
are  held  at  a considerable  distance  from  each  other  by  the 
thickness  of  the  intervertebral  substance,  and  by  the  corres- 
ponding length  of  the  oblique  processes;  but  this  space  is 
filled  up  by  a strong  flat  ligament,  which  goes  from  the  edge 
of  one  ring  to  the  edge  of  another,  and  so  extending  from  the 
articulating  processes,  backwards  to  the  spinous  processes, 
they  fill  up  all  the  interstice,  complete  the  canal  of  the  spinal 
marrow,  and  bind  the  bones  together  with  great  strength  :f 
these  are  assisted  in  their  office  of  holding  the  vertebrae  to- 

* The  LIGAM3NTUM  COMMUNE  ANTERIUS,  FASCIA  LONGITUDINALIS  ANTERIOR,  FASCIA  LIGA 
MENTOSA,  &c.  !'  :'wm  tills  ligameiil  in  the  loins  that  the  crura  diaphragraatis  arise,  witte 

tendons  flat  and  glisLCUing  like  the.iligament  itself,  and  hardly  to  be  distinguished  from  it. 

t They  are  named  the  iigamenta  subflava  crubum  PBOCESsuuti  sfinosorum. 


JOINTS  OF  THE  HEAD  AND  SPINE. 


289 


^ether,  by  a*  continuation  of  the  same  ligament,  or  of  a liga- 
mentous membrane  connected  with  it,  which  runs  all  the  way 
onwards  to  the  ends  of  the  spinous  processes,  where  they  are 
strengthened  by  accidental  fasciculi  ;*  and  in  the  middle  verte- 
bra of  the  back,  but  not  of  those  of  the  loins  or  neck,  similar 
ligaments  are  found  also  betwixt  the  transverse  processes.^ 
Next,  there  is  another  internal  ligament,  which  is  not  inter- 
rupted from  bone  to  bone,  but  runs  along  all  the  length  of  the 
spine,  within  the  medullary  canal,  and  it  corresponds  so  with 
the  external  vagina,  or  anterior  ligament  of  the  spine,  that  it  is 
called  the  posteriok  or  internal  ligament.J  It  begins  at  the 
occiput,  lies  flat  upon  the  back  part  of  the  bodies  of  the  verte- 
brae ; at  the  interstice  of  every  vertebrae  it  spreads  out  broad 
upon  the  intervertebral  substance,  doing  tbe  same  office  within 
that  the  intervertebral  ligaments  do  wflthout.  It  is  broader 
above ; it  grows  gradually  narroiver  towards  the  loins.  Al- 
though it  is  called  a vagina,  or  sheath,  it  does  by  no  means  sur- 
round nor  enclose  the  spinal  marrow,  but  is  entirely  confined 
to  tbe  covering  of  the  bodies  of  the  vertebra,  never  going  be- 
yond the  setting  off  of  the  articulating  surfaces,  or  the  place 
where  the  nerves  go  out.  It  adheres  firmly  to  the  bones,  and 
does  not  belong  at  all  to  the  spinal  marrow.  It  should  rather 
be  called  a ligament  for  the  bones,  than  a sheath  for  the  me- 
dulla. The  anterior  ligament  prevents  straining  of  the  spine 
backwards:  this  one  prevents  the  bending  of  the  spine  too 
much  forwards,  and  they  enclose  betwixt  them  the  bodies  of 
the  vertebrie,  and  their  intervertebral  substances. 

There  is  yet  a third  internal  ligament,  which  belongs  entirely 
to  the  neck;  it  is  called  apparatus  ligaivientosus  colli  ; it 
begins  from  the  edge  of  the  occipital  bone,  descends  in  the  ca- 
nal of  the  vertebrae,  is  thin  and  flat,  and  adheres  firmly  to  the 
body  of  each  vertebra,  covering  the  tooth-like  process.  The 
irregular  fasciculi,  or  bundles  of  this  ligament,  stretch  from 
bone  to  bone  ; and  the  whole  of  the  apparatus  ligamentosus 
extends  from  the  edge  of  the  occipital  hole  to  the  fourth  ver- 
tebra of  the  neck,  where  it  ends.  Its  chief  use  is  also  as  a liga- 
ment, merely  fixing  the  head  to  the  neck.  The  dura  mater  is 
within  these,  immediately  enclosing  the  spinal  marrow.  The 
ligaments  which  I have  just  named,  may  be  well  enough  allow- 
ed to  be  “ at  once  ligaments  for  tbe  bones,  and  a sheath  for 

* Theseare  named  the  mkmbhan«  intebspinales,  and  ligamenta  apices  spinariim  comi- 
TANTE9.  The  iigaments  which  tie  the  points  of  tbe  spines,  running  from  point  to  point,  make 
a long  ligament,  which  stretches  doivn  all  the  spine. 

t Called  LIGAMENTA  PHOCESsuuM  TnANSVERSORL'M,  and  found  only  from  the  6fth  to  the 
tenth  vertebra  of  the  back. 

t Fascia  liqamentosa  postica,  i.^fsciA  longiti'dinalis  postica,  lioamentum  commune 

S03TERIU3. 

VOL.  I.  O o 


290  JOINTS  OF  THE  HEAD  AND  SPINE. 

the  medulla.”  But  there  is  no  such  sheath  as  that  called  liga^ 
mentum  itifundibilifonne  by  Winslow  ; for  either  they  are 
peculiar  and  distinct  ligaments  for  the  bones,  such  as  1 have 
described,  or  they  belong  exclusively  to  the  medulla,  as  the 
dura  mater,  which  is  indeed  strengthened  at  certain  points, 
into  the  thickness  of  a ligament ; but  the  only  close  connec- 
tion of  the  spinal  marrow  with  the  ligaments  of  the  spine,  is 
just  at  the  hole  ol  the  occipital  bone;  and  for  a little  way 
down  through  all  the  rest  of  the  spine,  the  connection  is  by  the 
loosest  cellular  substance. 


OF  THE  LOWER  JAW. 

The  LOWER  JAW  is,  by  its  natural  form,  almost  a strict  ||| 

hinge,  and  the  lateral  motion,  in  grinding  is  but  very  slight. 

The  joint  is  formed  by  a deep  hollow  or  socket  in  the  temporal 
bone,  by  a ridge  which  stands  just  before  the  proper  socket, 
at  the  root  of  the  zygomatic  process,  and  by  a long  small 
head,  or  condyle,  which  is  placed  across  the  long  branch,  or 
condyloid  process  of  the  jaw.  These  form  the  joint ; and  the 
condyle,  the  hollow  of  the  temporal  bone,  and  the  root  of  the 
zygomatic  process,  are  all  covered  with  articulating  cartilage. 

I'he  joint  is  completed  by  a capsule  of  the  common  form, 
which  arises  from  the  neck  of  the  condyle,  and  which  is  so 
fixed  into  the  temporal  bone  as  to  include  both  the  proper 
•socket  and  the  root  of  the  zygomatic  process.  Thence  it  is 
manifest,  that  in  the  motions  of  the  jaw,  this  transverse  ridge 
is  required  as  a part  of  its  articulating  surface ; that  the  com- 
mon and  lesser  motions  are  performed  by  the  condyle  moving 
in  the  deepest  part  of  its  socket ; that  the  larger  and  wider 
openings  of  the  mouth  are  performed  by  such  depression  of 
the  jaw  as  makes  its  condyle  mount  upon  the  root  of  the  zygo- 
matic process.  While  the  luxation  of  the  jaw  is  a starting 
forwards  of  the  condyle,  till  it  is  lodged  quite  before  and  under 
the  zygomatic  process,  and  the  condyle  standing  upon  the  [ 
highest  ridge,  is  the  dangerous  position  in  which  luxation  i? 
most  easily  produced. 

To  render  these  motions  very  easy  and  free,  a moveable 
cartilage  is  interposed.  We  find  such  cartilages  in  the  joints 
of  the  clavicle,  wrist,  knee,  and  jaw,  because  the  motions  are 
continual  and  rapid.  The  moveable  cartilage  is  thin  in  its 
centre,  and  thicker  towards  its  edges,  by  which  it  rather 
deepens  than  fills  up  the  hollow  of  the  joint.  It  corresponds 
in  shape  with  the  head  or  condyle  of  the  jaw,  and  with  the 
hollow  of  the  temporal  bone.  It  moves  with  every  motion  of 


JOINTS  OF  THE  HEAD  AND  SPINE.  291 

tlie  jaw,  facilitates  the  common  motions,  and  prevents  lux- 
ation ; but  the  joint  is  still  more  strongly  secured  by  the 
strength  of  its  pterygoid  and  temporal  muscles,  which  are 
inserted  close  round  the  joint,  than  by  any  strength  of  its 
capsule.  It  is  the  muscles  which  prevent  luxation  ; and  it  is 
their  action  also  that  makes  luxation,  when  it  has  happened, 
so  difficult  to  reduce. 

RIBS. 

The  ribs  have  two  joints,  and  a hinge-like  motion,  rising 
and  falling  alternately,  as  we  draw  in  or  let  out  the  breath. 
The  two  joints  of  the  ribs  are  thus  secured  : First,  the  proper 
head  of  the  ribs  being  hinged  upon  the  intervertebral  sub- 
stance, and  touching  two  vertebrae,  it  is  tied  to  the  bodies  of 
each  by  a regular  capsule  ; the  bag  is  regular,  is  lubricated 
within,  and  is  as  perfect  as  any  joint  in  the  body ; it  is  radiated 
without,  so  as  to  expand  pretty  broad  upon  the  sides  of  the 
vertebrae,  and  has  a sort  of  division,  as  if  into  two  fasciculi, 
the  one  belonging  to  the  vertebra  above,  the  other  to  the  ver- 
tebra below  : they  gradually  vanish,  and  mix  with  the  perios- 
teum upon  the  bodies  of  the  vertebrae  ; these  are  named 
LiGAMENTUM  CAPiTELLi  cosTARUM,  as  belonging  to  the  little 
heads  of  the  ribs. 

The  back  of  the  rib  touches  the  forepart  of  the  transverse 
process,  and  is  articulated  there  : consequently  there  is  a 
small  capsular  ligament  belonging  to  this  joint  also  ; but  this 
joint  is  further  secured,  by  two  small  ligaments,  which  come 
from  the  transverse  process  of  the  vertebra,  and  take  hold  on 
the  neck  of  the  rib  : one  short  ligament  coming  from  the 
point  of  the  transverse  process,  is  behind  the  rib,  and  is  thence 
named  ligamentoivi  transversarium  externum;  another, 
rather  longer,  comes  from  the  inner  face  of  the  transverse 
process,  goes  a little  round  the  neck  of  the  rib,  is  implanted 
into  the  lower  edge  of  the  rib,  and  is  named  ligamentum 
TRANSVERSARIUM  INTERNUM  : another  Small  ligament  exactly 
opposite  to  this,  going  into  the  neck  of  the  rib,  upon  its  back 
part,  is  also  very  regular  ; and  other  subsidiary  ligaments  from 
different  points  assist  these  or  supply  their  place. 

Tbe  ribs  are  fixed  into  the  sternum  by  their  cartilages,  each 
of  which  has  a round  head,  a distinct  socket,  a regular  capsule, 
and  ligaments  which  expand  upon  the  surface  ofthe  sternum, 
much  in  the  same  way  that  the  ligamenta  capitelli  expand  up- 
on the  bodies  of  the  vertebr* : a tendinous  membrane  also 
inds  the  cartilages  of  the  ribs,  one  to  another,  crosses  over 
i e interstice,  and  so  covers  the  intercostal  muscles  with  a sort 


292 


JOINTS  OF  TITe 


of  fascia  ; and  the  whole  surface  of  the  sternum  and  that  of  the 
cartilages  is  covered  with  this  tendinous  expansion,  which  be- 
longs, confusedly,  to  the  origins  of  the  pectoral  muscles,  to  the 
ligaments  of  the  ribs  and  sternum,  and  to  the  periosteum  of 
that  bone. 


CHAP.  II. 


JOINTS  OF  THE  SHOULDER,  ARM,  AND  HAND. 


CLAVICLE. 


The  joining  of  the  clavicle  with  the  sternum  is  the  hinge 
upon  which  the  whole  arm  moves,  and  is  the  only  point  by 
which  the  arm  is  connected  with  the  trunk  : the  round  button- 
like head  of  the  clavicle  rolls  upon  the  aiticuiating  surface  of 
the  upper  bone  of  the  sternum  : it  is  in  such  continual  motion, 
that  some  particular  provision  is  required  ; and  accordingly  it 
has,  like  the  condyle  of  the  jaw,  a small  moving  cartilage,  which 
rolls  betwixt  this  head  and  the  sternum.  The  cartilage  is  titin, 
and  of  a mucous  nature  ; it  is  moveable  in  some  degree,  yet  it 
is  fixed  by  one  edge  to  the  head  of  the  clavicle.  This  joint  is 
enclosed  in  a strong  capsule,  consisting  first  of  a bag,  and  then 
of  an  outer  order  of  fibres,  which  go  out  in  a radiated  form, 
upon  the  surface  of  the  sternum,  like  the  ligaments  of  the  nhs; 
and  they  cross  and  cover  the  sternum,  so  that  the  ligaments  of 
the  opposite  side  meet ; and  this  meeting  forms  a cord  across 
the  upper  part  of  the  sternum,  which  is  named  interclavicu- 
LAR  LIGAMENT.  Thus  is  the  clavicle  fixed  to  the  sternum,  and 
another  broad  ligament  also  ties  it  to  the  first  rib. 

The  joining  of  the  clavicle  with  the  scapula  is  by  the  edge 
of  the  flat  clavicle  touching  the  edge  of  the  acromion  processes  | 
with  a narrow  but  flat  articulating  surface  : both  surfaces,  viz.fe 
of  the  acromion  and  of  the  clavicle,  are  covered  with  a thih1‘! 
articulating  cartilage  : in  some  subjects  a moveable  cartilageds 
also  found  here  ; it  is  a regular  joint,  and  is  very  seldorn^ 
obliterated  ; yet  its  motion,  though  continual,  is  not  vbry  free  j 
it  is  rather  a shuffling  and  bending  of  the  scapula  upon  this 
bone,  favouring  the  play  of  the  other  joints:  it  is  secured  first' 
by  a capsular  ligament,  which  is  in  itself  delicate  and  thin,  but" 
which  is  strengthened  by  many  ligamentous  bands,  which  pass  ^ 
^over  the  capsule)  betwixt  the  clavicle  and  the  acromion  pro--'|| 


SHOULDER,  ARM,  AND  HAND.  293 

cess ; the  clavicle,  as  it  passes  over  the  point  of  t,he  coracoid 
process,  is  tied  down  to  it  by  ligaments  of  considerable  strength ; 
one  comes  from  the  root  of  the  coracoid  process  to  the  clavi- 
cle, and  is  called  ligamentum  commune  conoidks  ; another 
from  the  point  of  the  coracoid  process,  is  implanted  into  the 
lower  or  inner  edge  of  the  clavicle,  and  is  named  ligamentum 
COMMUNE  TUAPEZoiDES ; trapczoid,  on  account  of  its  square 
form,  and  commune,  because  it  goes  from  the  scapula  to  the 
clavicle  ; while  other  ligaments,  going  from  one  process  of  the 
scapula  to  another,  are  named  proper  or  peculiar  ligaments  of 
the  scapula.  The  ligamentum  proprium  triangulare  stretches 
from  the  coracoid  process  to  the  acromion  process  of  the  scapu- 
la, The  LIGAMENTUM  SCAPULA:  PROPRIUM  POSTERIUS  is  of  leSS 
importance,  being  that  which  completes  the  notch  of  the 
scapula  into  a bole,  and  gives  attachment  to  the  omo-hyoideus 
muscle. 


SHOULDER-JOINT. 

The  SHOULDER  is  one  of  the  most  beautiful  joints,  loose  and 
moveable,  very  free  in  its  motions,  but  very  liable  to  be  displa- 
ced. To  form  this  joint,  the  humerus  has  a large  round  and 
flattened  head ; the  cavity  of  the  scapula,*  which  receives  this 
head,  is  oval,  or  triangular,  small  and  very  shallow ; it  is  eked 
out  with  a thick  cartilaginous  border,  which  increases  the  hol- 
low of  the  socket,  but  still  it  is  so  shallow,  that  the  humerus 
cannot  be  so  much  said  to  be  lodged  in  the  glenoid  cavity  as 
to  be  laid  upon  it  Its  capsule  or  bag  is  very  loose  and  wide, 
coming  from  the  edges  of  the  glenoid  cavity,  and  implanted 
round  the  neck  of  the  bone  : the  joint  is  richly  bedewed  with 
mucus,  or  rather  with  a mixed  secretion,  which  is  partly  secre- 
ted by  a fimbriated  organ,  consisting  of  lacunas  or  bags,  the 
common  organ  for  this  secretion  through  all  the  joints,  and  by 
a thinner  exudation  from  those  extreme  arteries,  w’hich  termi- 
nate, with  open  mouths,  upon  the  internal  surface  of  the  bag. 

By  the  shallowness  of  its  socket,  and  the  largeness  of  its 
head,  by  the  looseness  of  its  capsule,  by  all  the  forms  and  cir- 
cumstances of  its  structure,  the  shoulder  is  exceedingly  loose, 
and  very  liable  to  be  displaced  ; it  has  this  loose  structure,  and 
superficial  socket,  that  its  motions  may  be  free,  but  seldom  is 
there  any  great  advantage  gained  in  the  human  body,  without 
a counterbalance  of  weakness  and  danger;  and  every  where 
in  the  limbs  we  obseiwe  that  a joint  is  w eak  and  liable  to  luxa- 

^ It  is  called  glenoid  cavity,  from  tha  Greek  Dame  of  a joint,  and  the  name  is  not  abso 
lately  appropriated  to  tlio  scapula. 


29-4 


JOINTS  OP  THE 


tion  in  proportion  as  its  motions  are  free  and  large.  Yet  the 
shoulder-joint  is  not  vvitfiout  some  kind  of  defence  ; its  socket 
is  oliallow,  but  it  is  guarded  by  the  largest  projecting  processes 
in  all  the  body,  b)  the  acromion  projecting  and  strengthening 
it  above,  and  by  tl)e  coracoid  process  within;  its  ligament  is 
lax,  easily  torn,  and  useful  rather  for  confining  the  synovia, 
and  keeping  the  head  of  the  liumerus  opposite  to  its  proper 
cavity,  than  in  securing  the  joint  by  any  strength  it  has  : there- 
fore a ligament  extends  from  the  coracoid  to  the  acromion 
process,  (ligamentum  pkophium  tiuangulare  scapulae,) 
which  completes  the  defences  of  the  joint  above,  and  at  its  in- 
ner side.  The  capsule  is  perforated  by  the  long  tendon  of  the 
biceps  muscle,  and  the  hole  by  which  it  enters  is  called/o?-amcw 
ovale,  and  on  each  side  of  this  hole  the  ligament  is  much 
strengthened ; and  there  comes  also  from  the  point  of  the 
acromion  process  an  additional  ligament,  which  adheres  to  the 
capsule  : but  the  circumstance  from  which  the  chief  strength 
of  the  shoulder-joint  is  derived,  is  the  insertion  of  the  four 
muscles  which  come  from  the  scapula  close  round  the  head  of 
the  bone,  so  that  they  adhere  to  the  capsular  ligament,  pull  it 
up  to  prevent  its  being  checked  in  the  motions  of  the  joint, 
strengthen  it  by  their  thickness,  for  they  are  spread  upon  it  : 
and  the  contraction  of  the  muscles  hold  the  humerus  in  its 
place  ; their  total  relaxation  (as  in  certain  cases  of  weakness) 
suffers  the  humerus  to  drop  away  from  the  scapula,  without  any 
fall  or  accident,  forming  what  we  are  accustomed  to  call  a luxa- 
tion of  the  humerus,  from  an  internal  cause  ; and  the  shoulder 
cannot  be  luxated  by  a fall,  without  such  violence  as  tears  up 
the  tendons  of  these  muscles.  We  must  add  to  this  anatomy 
of  the  joint,  that  it  is  surrounded  by  numbers  of  bursas  or  mu- 
cous bags  one  under  the  tendons  of  the  subscapularis ; one 
under  the  short  head  of  the  biceps  muscle;  one  betwixt  the 
coracoid  process  and  the  shoulder-bone ; and  one  under  the 
acromion  process  of  the  scapula,  exceedingly  large  : and  these 
are  so  fairly  parts  of  the  joint,  that  very  commonly  they  open 
into  it  with  communications,  either  perfectly  natural  or  at  least 
not  hurtful,  either  originally  existing  or  formed  by  continual 
friction.  It  should  also  be  remembered,  that  the  long  tendi- 
nous head  of  the  biceps  muscle  comes  from  the  margin  of  the 
socket,  directly  over  the  ball  of  the  os  humeri,  and  through 
the  capsule,  by  the  foramen  ovale. 

* Vide  Monro’s  tables  of  the  bursy  mucosse,  where  all  these  parts  are  represented,  the 
knowledge  of  wiiich  is  so  very  useful  for  the  surgeon.  I have  opened  this  great  bursa  under 
the  acromion  process,  and  let  out  four  pounds  of  the  peculiar  mucus  and  gelatinous  lumpS: 
nvith  wiiich  the  diseased  bursae  arc  commonly  611ed. 


SHOULDER,  ARM,  AND  HAND. 


295 


ELBOW. 

The  ELBOW-JOINT  is  formed  by  three  bones  ; the  humerus, 
tadius,  and  ulna : the  ulna  bends  backwards  and  forwards  upon 
the  shoulder-bone  ; the  radius  bends  upon  the  shoulder-bone 
along  with  the  ulna ; it  always  must  accompany  the  ulna,  but 
it  also  has  a motion  of  its  own,  rolling  in  circles ; its  round 
button-like  head  rolling  continually  with  its  edge  upon  a socket 
in  the  ulna,  and  with  its  flat  face  upon  the  tubercle  of  the  hu- 
merus. The  whole  composes  one  joint,  and  is  enclosed  in  one 
capsule ; the  bones  accompany  each  other  in  their  luxations, 
as  well  as  in  their  natural  motions  : the  ulna  is  never  dislocated 
without  the  radius  being  also  displaced  ; a circumstance  w'hich 
is  but  too  little  noticed,  and,  so  far  as  I remember,  hardly  con- 
sidered or  known. 

The  radius  and  ulna  are  united  principally  by  the  interos- 
seous LIGAMENT,  which,  as  it  extends  in  the  whole  length  of 
the  bones,  has  great  strength.  Towards  the  elbow'  this  liga- 
ment is  deficient  for  a space,  and  it  is  perforated  by  vessels. 
The  CHORDA  TRANsvERSALis  cuBiTi  is  an  oblique  slip  of  li- 
gament which  passes  from  the  tubercle  of  the  ulna  obliquely 
downwards  and  across  to  the  radius. 


LIGAMENTS  OF  THE  ELBOW-JOINT. 

The  general  capsule  arises  from  the  humerus,  from  both 
the  tubercles,  and  all  round  the  two  hollows  which  receive  the 
olecranon  and  coronoid  processes  of  the  ulna ; it  is  implanted 
again  into  the  tip  of  the  olecranon,  and  all  round  that  sigmoid 
cavity  which  receives  the  lower  end  of  the  humerus,  and  all 
round  the  edge  of  the  coronary  process.  It  is  also  fixed  round 
the  neck  of  the  radius;  it  comprehends,  in  one  bag,  the 
humerus,  radius,  and  ulna ; and  unites  them  into  one  joint, 
performing  two  motions,  viz.  flexion  and  extension  by  the 
ulna,  and  rolling  by  the  radius;  the  joint  is  lubricated  by 
mucus*  and  by  fat,  which  is  found  chiefly  about  the  olecranon : 
and  that  the  bones  may  be  further  secured,  additional  liga- 
ments are  spread  out  upon  them,  which  are  all  without  the 
common  capsule  of  the  joint  lying  upon  it,  and  strengthening 
it  at  the  necessary  points. 

1.  There  is  the  common  capsule  enclosing  the  whole.  2. 
It  is  the  form  of  every  hinge-joint  (and  this  is  one  of  the  purest) 

* The  oil  contained  in  the  adipose  membrane  never  exudes  in  the  living  body,  and  cannot 
iubricate. 


296 


JOINTS  OF  THE 


to  have  its  capsule  strengthened  at  the  sides  ; and  the  sides  of 
this,  the  elbow-joint,  are  strengthened  by  two  fasciculi,  or 
ligamentous  heads,  which,  coming  from  the  tubercles  of  the 
humerus,  spread  a little  upon  the  capsule,  and  adhere  to  it 
like  part  of  its  substance.  One,  from  the  outer  condyle, 
spreads  upon  the  neck  of  the  radius,  and  sends  a strong  division 
to  be  attached  to  the  rough  spine  of  the  ulna,  which  is  near  the 
lesser  sigmoid  cavity  of  the  ulna.  This  is  of  course  the  ex- 
ternal LATERAL  LIGAMENT.  Another  ligament,  from  the  in- 
ner condyle  of  the  humerus,  goes  upon  the  inside  of  the  capsule 
and  strengthens  it  there  : it  is  implanted  in  the  prominence  on 
the  inner  edge  of  the  coronoid  process  of  the  ulna,  and  is 
named  the  internal  lateral  ligament.*  The  continual 
rolling  motion  of  the  radius  requires  a peculiar  ligament,  and 
this  peculiar  ligament  of  the  radius  is  named  ligamentum 
COGONARKJM,  or  ANNULARE,  because  it  encircles  the  neck  of 
the  radius;  annulare  or  orbiculare  from  its  hoop  or  ring- 
like from  : it  is  a very  strong  and  narrow  stripe  or  band,  which 
arises  from  that  part  of  the  ulna  where  the  radius  rolls  upon  it, 
and  surrounds  the  radius,  making  at  least  two  thirds  of  a cir- 
cle ; and  so  having  turned  over  the  neck  of  the  radius,  is  in- 
serted into  the  opposite  side  of  the  ulna.  This  is  commonly 
described  as  a distinct  ligament  surrounding  the  neck  of  the 
radius,  and  having  the  common  capsule,  implanted  into  its 
upper  edge ; but,  in  truth,  it  is  like  the  others,  a thicker  band 
of  the  common  capsule,  but  with  a distinction  much  more 
particular  here  by  the  contrast  of  the  great  thickness  of  the 
coronary  ligament,  and  the  extreme  thinness  of  the  capsule 
at  the  fore  part : for  the  capsule  of  every  hinge-joint  is  strong 
only  at  its  sides ; other  bands  from  the  outer  condyle,  and 
from  the  coronary  process  of  the  ulna,  strengthen  this  liga- 
ment of  the  radius,  and  are  known  by  the  name  of  accessory 
LIGAMENTS  of  the  coronoid  ligament,  as  the  lateral  ones  are 
known  by  the  name  of  accessory  ligaments  to  the  cap- 
sule.f 

So  that  there  is,  1.  A complete  capsule  which  encloses  all 
the  bones;  2.  Lateral  ligaments  which  make  the  main 
strength  of  the  joint ; 3.  A coronary  ligament  which  regulates 

* I see  anntlier  ligament  behind  the  internal  lateral  ligament,  viz.  arising  from  the  ex- 
ternal condyle,  and  inserted  into  the  side  of  the  olecranon.  There  are  in  truth  two  internal 
lateral  ligaments,  and  their  operation  is  not  merely  to  confine  the  motion  of  the  joint 
laterally,  but  to  check  the  flexion  and  extension  of  the  arm ; the  one  being  made  tense  by 
tlie  flexion,  the  other  by  the  extension,  of  the  fore-arm. 

t But  the  cap.sule  ought  to  be  called  merabrana  capsiilaris  ; it  is  not  a ligament,  and 
these  which  are  called  acceseoly  are  proper  ligaments.  The  ligament  which  is  on  the  fore 
part  of  the  joint,  and  which  runs  towards  the  Ligamentum  Annulare,  is  properly  called 
Acerssorium  Annuli  Aniicum;  it  crosses  from  the  ulna  to  the  external  condyle;  and 
another  coming  round  from  the  olecranon,  and  being  on  the  back  of  the  joint,  Accestonum 
Annulare  Fosticum. 


SHOULDER,  ARM,  AND  HAND. 


297 


and  strengthens  the  rolling  motions  of  the  radius,  and  keeps 
it  firm,  turning  like  a spindle  in  its  bush.  The  whole  joint 
is  surrounded  with  cellular  substance  : the  regularity  of  its 
ligaments  is  confounded  by  the  adhesions  of  muscles  and 
tendons : though  it  is,  on  the  whole,  weak  behind  and  be- 
fore, and  very  strong  at  its  sides,  yet  tendinous  and  ligamen- 
tous fibres  cross  it  in  all  directions  : so  that  the  capsule  and  its 
assisting  ligaments  are  irregular  and  rough  without ; but  gela- 
tinous, smooth,  and  glossy  within. 


WRIST. 

The  WRIST  is  one  of  the  most  moveable  joints  in  the 
body,  having  the  strength  of  a mere  hinge-joint ; (because 
it  is  almost  a strict  hinge,  by  the  connection  of  the  long  ball 
of  the  carpus  with  the  long  hollow  of  the  radius,)  and  hav- 
ing, at  the  same  time,  all  the  properties  of  the  most  move- 
able  joint  by  the  free  turning  of  the  radius,  without  the 
weakness  which  is  peculiar  to  the  circular  and  free  moving 
joints.  These  distinctions  divide  the  wrist-joint  into  its  two 
parts. 

1.  The  articulation  formed  by  the  scaphoid  and  lunated 
bones,  which  form  an  oval  ball  of  articulation,  and  the  great 
scaphoid  cavity  of  the  radius  which  receives  this  ball : the  end 
of  the  ulna  does  not  properly  enter  into  the  cavity  of  the 
wrist,  but  its  end,  or  little  round  head,  is  covered  with  a 
moveable  cartilage,  and  that  cartilage  represents  the  end  of 
the  ulna.  It  is  called  cartilago  intermedia  triangularis. 
Now,  this  first  joint,  viz.  of  the  scaphoid  and  lunated  bones, 
the  head  of  the  radius,  and  the  moveable  cartilage  which  re- 
presents the  head  of  the  ulna,  are  surrounded  by  the  general 
capsule  or  bag  of  the  joint.  The  capsule  arises  from  the 
ends  of  the  radius  and  of  the  ulna ; from  the  styloid  point  of 
the  one,  round  to  the  same  point  of  the  other ; and  is  im- 
planted near  the  lower  rank  of  the  carpal  bones ; though  it 
adheres  first  to  the  scaphoid  and  limated  bones,  it  passes  them 
going  over  all  the  bones  of  the  carpus,  especially  in  the  palm, 
so  as  to  add  strength  to  their  peculiar  ligaments ; and  in  the 
palm,  'the  tendons  for  the  fingers  run  over  it : so  it  forms  on 
one  side  an  additional  ligament  for  the  carpus  ; on  the  other, 
it  forms  the  floor  of  the  tendinous  sheath,  a smooth  and  lu- 
bricated surface  for  the  tendons  to  run  upon.  This  general 
ligament  is  strengthened  by  particular  ones  coming  from  the 
styloid  processes  of  the  radius  and  of  the  ulna,  which  spread 
upon  the  bones  of  the  carpus,  and  may  be  described  as  lateral 

VOL.  I.  Pp 


298 


JOINTS  OP  THE 


ligaments ; for  although  the  wx’ist  joint  is  not  accurately  a 
hinge,  yet  it  partakes  most  of  that  character,  and  the  liga- 
ments are  strongest  at  the  radial  and  ulnar  edges  of  the  wrist. 
But  there  are  so  many  irregular  points  of  bone  about  the 
wrist,  that  the  little  fasciculi,  with  which  this  capsule  is 
covered  and  strengthened,  are  innumerable.  Within  this 
joint,  and  stretching  from  the  groove  betwixt  the  scaphoid  and 
lunated  bones,  there  is  an  internal  ligament  of  a soft  and  pulpy 
nature ; it  is  named  ligamentum  mucosum  ; but  the  very  name 
shows,  that  it  is  less  valuable  as  a ligament  (since  the  joint  is 
already  well  enough  secured,)  than  as  a conductor  for  the 
lacunee  or  ducts  which  separate  the  mucus. 

2.  The  articulation  by  which  the  hand  performs  all  its  turn- 
ing motions  is  that  of  the  radius  with  the  ulna  : this  is  set  apart 
altogether  from  the  general  articulation  of  the  joint.  The 
lateral  cavity  of  the  radius  receives  the  little  round  head  of 
the  ulna;  they  are  enclosed  in  their  own  peculiar  capsule, 
which  is  so  loose  about  the  bones,  that  although  it  is  a regular 
capsule  of  the  common  form,  it  has  the  name  of  meiyterana 
CAPsuLARis  SACCiFORMis.  Tlius  there  is  one  joint  within 
another  ; a moveable  cartilage  betwixt  them,  and  the  capsule 
of  the  one,  the  more  moveable  joint,  peculiarly  wide,  and 
not  so  strong ; all  which  should  be  considered  in  thinking 
about  luxations  of  the  wrist. 

The  carpal  bones  are  connected  with  each  other  so  very 
closely,  that  the  name  of  joint  can  hardly  be  used.  They  are 
rather  fixed  than  jointed  together.  Each  bone  has  four 
smooth  articulating  surfaces,  by  which  it  is  united  to  the  ad- 
joining bones.  The  first  two  bones  form  the  great  ball  of  the 
wrist ; the  second  row  again  is  united  with  the  first,  by  a sort 
of  ball  and  socket ; for  the  os  magnum,  which  is  the  central 
hone  of  the  second  row,  has  a large  round  head,  which  is  re- 
ceived into  the  lunated  hollow  of  the  os  lunare,  which  is  the 
central  bone  of  the  first  row.  The  first  row  is  thus  united  to 
the  second,  by  a distinct  and  general  capsule,  in  addition  to 
which  each  single  bone  is  tied  to  the  next  adjoining,  by  a re- 
gular capsular  ligament  within,  and  by  flat  cross  ligaments 
without,  or  rather  by  many  bundles  of  ligaments,  which  cross 
each  other  in  a veiy  complicated  manner,  and  the  little  flat 
and  shining  fasciculi  give  the  whole  a radiated,  or  star-like 
form.* 

The  metacarpal  bones  are  also  joined  to  the  carpal  in  one 

* These  are  the  ligaments  which  are  really  so  unimportant  to  the  anatomist,  or  to  the 
-urgeon,  but  which  are  so  laboriously  described  under  the  titles  of  ligamenta  brevja, 
oBLiQUA  TRANsvERSARiA,  and  PROPRIA  ossiuffl  Carpi ; for  they  do  in  fact  cross  and  traverre 
' he  earprrs  in  every  possible  direction. 


SHOULDER,  ARM,  AND  HAN».  29^ 

VOW,  by  a line  of  joints,  which  are  as  one  joint ; besides  their 
common  capsule,  the  metacarpal  of  each  finger  has  its  pecu- 
liar ligaments  proceeding  in  a radiated  or  star-like  form  from 
the  carpal  bones,  and  going  out  broad  upon  the  metacarpal 
bones,  and  so  numerous,  that  each  metacarpal  bone  is  se- 
curely tied  by  ligaments  to  one  or  two  of  the  bones  of  the 
carpus ; * and  at  their  heads,  where  the  fingers  are  implant- 
ed upon  them,  forming  the  knuckles,  they  are  again  tied  by 
flat  ligaments,  which  go  from  head  to  head  of  the  metacarpal 
bones,f  binding  them  together,  permitting  a slight  bending 
towards  each  other,  so  as  to  make  a hollow'  in  the  hand,  but 
no  such  wide  motion  as  might  assist  the  fingers  ; they  are 
but  as  a foundation  upon  which  the  fingers  stand  and  move. 


FINGERS. 

The  joints  of  the  fingers  are  formed  by  round  heads  in  the 
upper  end  of  one  row  of  bones,  and  by  hollow  sockets  on 
the  lower  ends  of  the  next  row ; each  joint  is  qualified  by 
the  round  form  of  its  heads,  to  be  a circular  and  free  moving 
joint ; but  it  is  restricted  by  the  forms  of  its  ligaments,  to  the 
nature  of  a hinge-joint ; for  each  finger-joint  is  included  first 
in  a fair  round  capsule,  or  bag,  of  the  ordinary  form,  but  that 
capsule  is  strengthened  by  very  distinct  lateral  ligaments 
upon  its  sides,  which  lateral  ligaments  form  the  chief  strength 
of  the  joints ; above  these  lateral  ligaments  the  joint  is 
strengthened  by  a broad  fascia,  or  sheath,  which  comes  from 
the  tendons  of  the  interossei  muscles,  covers  the  backs  of 
all  the  fingers,  which  is  especially  strong  over  the  joints.  One 
part  of  the  apparatus  of  the  wrist-joint  is  the  smooth  and 
lubricated  sheath,  in  w'hich  the  tendons  of  the  fingers  run. 
It  is  formed  in  part  by  the  outer  side  of  the  capsule  of  the 
wrist,  and  in  part  by  that  bridge  of  ligament  which  proceeds 
from  the  four  corner  points  of  the  carpal  bones.  This  sheath 
is  lined  with  a delicate  and  softer  modification  of  the  common 
tendinous  membrane,  is  fully  bedewed  with  mucus,  and  is 
fairly  to  be  ranked  with  the  bursfe  mucosBe,  as  it  is  indeed, 
like  them  a shut  sack.  But  it  is  farther  crossed  in  such  a 
manner  by  partitions  belonging  to  each  flexor  tendon,  that 
each  of  them  may  be  said  to  have  its  appropriated  bursa 
mucosa.  And  these  bursae,  to  prevent  the  bad  conse- 
quences of  friction,  are  put  both  betwixt  the  cross  ligament 
and  the  tendons,  and  also  betwixt  the  tendons  of  the  upper- 

* And  these  also  are  named  according  to  their  several  directions,  uoamksta  AKTirc 

Lir.IA,  LATERALIA,  RECTA  PERPENDICULARIA,  &C. 

t These  are  named  the  uoament.v  ia'terossea. 


300 


JOINTS  OF  THE 


most  muscle,  and  of  the  deeper  one,  and  again  betwixt  the 
tendons  of  the  fingers  and  of  the  thumb. 

In  the  same  way  the  sheaths  of  the  tendons,  as  they  run 
along  the  fingers,  may  be  considered  as  part  of  the  apparatus 
of  their  joints  ; for  the  first  set  of  burs®,  viz.  those  which  lie  in 
the  palm  of  the  hand,  stop  before  they  reach  the  first  joints 
of  the  fingers,  and  then  other  longitudinal  burs®  begin  from 
the  first  joint  of  the  fingers,  and  go  all  along  them  to  the  last 
joint,  forming  a sheath  for  the  tendons  to  run  in,  which  does 
at  once  the  office  of  a strong  ligament,  binding  them  dowm  in 
their  places,  and  which  is  so  lubricated  on  its  internal  surface, 
as  to  save  the  necessity  of  other  burs®.  These  sheaths  are 
thicker  in  certain  points,  so  as  to  form  cross  rings  of  strong 
ligament;  but  the  common  sheath,  and  these  thicker  rings, 
still  form  one  continued  canal;  these  are  named  the  sheaths 
and  ANNULAR  LIGAMENTS,  Or  CROSS  LIGAMENTS  * of  the 
fingers,  and  are  of  the  same  nature  with  the  burs®.  Be- 
sides these,  there  are  no  distinct  burs®  on  the  fingers,  but 
there  are  several  about  the  wrist,  and  one  especially  of  consi- 
derable size  at  the  root  of  the  thumb.f 


CHAP.  III. 


.lOlNTS  OF  THE  THIGH,  LEG,  AND  ANKLE. 
OF  THE  HIP-JOINT. 


1 HE  acetabulum,  which  is  rough  in  the  naked  bone,  is  natu- 
rally lined  with  a thick  and  very  smooth  cartilage.  The  head 
of  the  thigh-bone  is  covered  with  a similar  cartilage,  also  very 
thick  and  smooth  ; and  these  cartilages  almost  fill  up  that  deep 
dimple  which  is  seen  in  the  centre  of  the  bead  of  the  thigh- 
bone, and  smooth  that  hole  which  is  formed  in  the  centre  of 
the  socket,  by  the  meeting  of  the  several  pieces  of  which  it  is 
composed.  The  socket  is  not  only  deep  in  its  bones,  but  is 
further  deepened  by  the  cartilage  which  tips  the  edge  of  the 
socket,  and  which  stands  up  to  a considerable  height.  The 
socket  is  imperfect  at  that  side  which  looks  towards  the  thyroid 
hole ; the  bony  edge  is  entirely  wanting  there,  and  the  space 

* LiGAMHNTA  VAGINALl/,  LIGAMEKTA  CRUCIATA,  PHALAKGGM,  &€. 

t Vide  Monro’s  Bureae  Mucosae. 


THIGH,  LEG,  ANB  ANKLE. 


301 


is  filled  up  by  a strong  cartilaginous  ligament,  which  goes 
across  this  gap,  from  the  one  point  to  the  other,  and  from  its 
going  across  is  named  the  ligamentum  labhi  cartilagin^i 
TRANSVERSALE.'*^  The  capsular  ligament  of  the  hip-joint  is 
the  thickest  and  strongest  of  all  the  body.  It  is,  like  other  cap- 
sules, a reflection  and  thickening  of  the  periosteum  ; the  peri- 
osteum coming  along  the  outside  of  the  bone,  leaves  it  at  the 
edge  of  the  socket.  The  periosteum,  or  rather  perichondrium 
from  the  inside  of  the  socket,  comes  up  to  the  edge,  and  meets 
the  outer  layer.  They  unite  together,  so  as  to  form  the  gene- 
ral capsule  enclosing  the  ring-like  cartilage,  which  tips  the 
edge  of  the  socket  between  them.  This  ligament  encloses  all 
the  bones  from  the  edges  of  the  socket  to  the  roots  of  the  tro- 
chanters, embracing  not  only  the  head,  but  the  neck  of  the 
thigh-bone.  The  outer  plate,  continuous  with  the  periosteum, 
is  thick  and  strong,  and  is  assisted  by  much  cellular  substance 
condensed  round  it,  and  it  is  further  thickened  by  slips  which 
come  from  the  iliacus,  gluteus,  and  other  muscles  which  pass 
over  the  joint,  while  the  external  plate  of  the  ligament  lines 
the  whole  with  a soft  and  well  lubricated  coat. 

In  addition  to  this  general  capsule,  there  are  two  internal 
ligaments,  1st,  The  round  ligament,  as  it  is  called,  which  comes 
from  the  centre  of  the  socket  to  be  fixed  into  the  centre  of 
the  ball  of  the  thigh-bone.  It  is  not  round,  but  flat  or  trian- 
gular. It  has  a broad  triangular  basis,  rooted  in  the  socket 
exactly  at  that  place  where  the  several  bones  of  the  socket 
meet,  forming  a triangular  ridge,  which  gives  this  triangular 
form  to  the  central  ligament.  It  has  three  angles,  and  three 
flat  sides.  It  is  broad  where  it  arises  from  the  bottom  of  the 
socket,  is  about  an  inch  and  a half  in  length,  grows  narrower 
as  it  goes  outwards  towards  the  head  of  the  bone,  and  is  al- 
most round  where  it  is  implanted  into  the  dimple  in  the  head 
of  the  thigh-bone,  at  which  point  it  is  so  fixed,  as  to  leave  a 
very  remarkable  roughness  in  the  naked  bone.  But  round  the 
roots  of  this  ligament,  and  in  the  bottom  of  the  socket,  there 
is  left  a pretty  deep  hollow,  which  is  said  to  be  filled  up  with 
the  synovial  gland.  It  is  w'onderful  how  easy  authors  talk  of 
the  synovial  gland,  as  if  they  had  seen  it ; they  describe  very 
formally  its  affections  and  diseases,  as  when  hurt  by  a blow 
upon  the  trochanter ; yet  there  is  no  distinct  gland  to  be  found. 
There  is  a fringed  and  ragged  mass  lodged  in  the  bottom  of 
the  socket,  hanging  out  into  the  hollow,  and  continually  rubbed 
by  the  ball  of  the  thigh-bone  in  its  motions : the  fringes  and 

• This  ligament  is  double,  that  is,  there  is  one  on  the  inside  of  the  edge,  and  one  on  the 
outside;  tlience  it  is  often  reckoned  as  two  ligaments,  viz.  ligamentpm  thansversale  k- 

TesiU'M  et  IITEHNCM. 


302 


JOINTS  OP  THE 


points  certainly  are  ducts  from  which  we  can  squeeze  ©ut 
mucus  ; but  it  is  by  no  means  proved  that  they  belong  to  a 
synovial  gland,  and  it  looks  rather  as  if  the  ducts  were  them- 
selves the  secreting  organ,  like  the  lacunae,  or  mucous  bags 
in  the  tongue,  or  in  the  urethra,  vagina,  oesophagus,  and 
other  hollow  tubes.  Such  a structure  is  fitter  for  suffering  the 
strong  pressure  and  continual  action  of  the  thigh-bone,  than 
any  determined  gland.  We  see,  then,  nothing  but  mucous 
ducts  of  a fringed  form,  hanging  down  from  this  hollow  into 
the  cavity  of  the  joint,  a quantity  of  fat  accompanying  these 
fringes,  and  a pappy  mucous  membrane,  which  keeps  these 
fringes  and  fatty  membranes  orderly,  and  in  their  places,  and 
which  ties  them  so  to  the  angles  of  the  triangular  ligament, 
that  they  must  move  with  the  motions  of  the  joint.  This 
mucous  membrane,  which  keeps  these  fatty  fringes  orderly, 
has  two  or  three  small  bridles  in  different  directions,  whence 
they  are  named  the  ligamenta  mucosa,  or  ligamentula 
massee  adiposfe  glandulosa  ; and  this  may  be  considered  as  the 
continued  inflection  of  the  softer  internal  lamella  of  the  cap- 
sule, which  not  only  lines  the  socket,  but  is  reflected  over  the 
central  ligament,  and  over  the  globe  of  the  thigh-bone,  cover- 
ing them  also  with  a delicate  mucous  coat.  Other  fringes  of 
the  same  kind  are  found  at  the  lower  part  of  the  joint,  lying 
round  the  neck  of  the  thigh-bone,  near  the  angle  where  the 
capsular  ligament  is  implanted  into  the  root  of  the  great 
trochanter  : the  liquor  from  these  mucous  fimbriae,  with  the 
general  serous  exudations,  are  mixed  and  blended  for  lubri- 
cating the  joint. 

This  capsule,  which  is  naturally  the  thickest  and  strongest 
in  the  body,  almost  a quarter  of  an  inch  in  thickness,  is  farther 
strengthened  by  many  additions ; for  a slip  of  very  strong 
tendinous  or  cellular  substance  condensed,  comes  down  from 
the  lower  spinous  process  of  the  os  ilium,  and  spreads  out  over 
the  capsule,  and  strengthens  it  very  much  on  its  forepart ; the 
smallest  of  the  glutaei  muscles  adheres  to  the  capsule,  and 
strengthens  it  behind ; the  psoas  magnus  and  iliacus  internus 
pass  by  the  inner  side  of  the  capsule,  and  though  they  do  not 
absolutely  adhere  to  it,  they  deposit  much  cellular  substance, 
which  is  condensed  so  as  to  strengthen  the  capsule,  forming  at 
the  same  time  a large  bursa  mucosa,  betwixt  their  tendinous 
fibres  and  the  joint.  That  tendon  of  the  rectus  muscle  which 
comes  from  the  margin  of  the  socket,  lies  upon  the  outer  side 
of  the  capsule,  adheres  to  it,  and  strengthens  it.  The  secu- 
rity of  the  hip-joint  seems  to  depend  more  upon  the  strength 
of  its  capsular  ligament,  than  that  of  almost  any  other  joint. 


THIGH,  LEG,  AND  ANKLE. 


303 


THE  KNEE-JOINT. 

The  knee-joint  is  one  of  the  most  superficial  joints,  and 
one  of  the  weakest,  so  far  as  relates  to  the  bones,  for  the  flat 
condyles  of  the  thigh-bone  are  merely  laid  upon  the  flat  head 
of  the  tibia.  There  is  here  no  fair  cavity,  receiving  a large 
head  as  in  the  joint  of  the  hip  ; no  slighter  ball  and  socket,  as 
in  the  fingers ; no  strong  over-hanging  bones,  as  in  the 
shoulder;  no  hook-like  process,  as  in  the  ulna.  This  is  not 
a hinge-joint,  like  the  ankle,  secured  between  two  points  of 
bone.  We  do  not  find  the  means  of  strength  in  its  bones, 
but  in  the  number,  size,  and  disposition  of  the  great  liga- 
ments with  which  its  bones  are  joined ; by  virtue  of  these 
ligaments  it  is  the  strongest  joint  of  the  human  body,  the 
most  oppressed  by  great  loads,  the  most  exercised  in  continual 
motions,  yet  less  frequently  displaced  than  any  other.  But 
this  complication  of  ligaments,  which  gives  it  mechanical 
strength,  is  the  very  cause  of  its  constitutional  weakness, 
makes  it  very  delicate,  and  very  liable  to  disease. 

The  bones  which  compose  this  joint  are  the  tibia,  thigh- 
bones, and  patella;  and  they  are  united  by  many  ligaments, 
both  within  and  without  the  joint. 

1.  The  CAPSULE  of  the  knee  is  naturally  very  thin  and 
delicate,  transparent  as  a cobweb.  This  thin  capsule  comes 
from  the  forepart  of  the  thigh-bone,  all  round  the  articula- 
ting surfaces,  whence  it  goes  downwards  by  the  sides  of  the 
condyles ; from  this  origin  it  is  inserted  into  all  the  edge  of  the 
rotula,  and  in  such  a way  as  to  keep  the  rotula  properly  without 
the  cavity  of  the  joint,  the  capsular  ligament  going  over  its  inner 
surface,  and  lining  it  with  a smooth  and  delicate  coat.  It  is 
fixed  below  into  all  the  circle  of  the  head  of  the  tibia,  and 
thus  completes  its  circle,  embracing  all  the  bones.  This 
capsule,  naturally  so  thin  and  delicate,  is  made  up  from  all 
the  surrounding  parts  to  a considerable  thickness  ; first,  it  is 
covered  behind  by  the  heads  of  the  gastrocnemii ; at  the 
sides,  by  the  biceps,  and  other  muscles  of  the  ham-strings ; 
on  its  forepart,  it  is  strengthened  by  the  general  fascia  of  the 
thigh,  which  goes  down  over  the  knee,  and  being  there  re-in- 
forced  both  by  its  adhesion  to  the  bones,  and  by  the  broad 
expansion  of  the  vastus  internus,  sartorius,  biceps,  and  other 
muscles,  which  go  out  over  the  patella,  it  adheres  to  the  cap- 
sule, and  makes  tlie  whole  very  strong ; besides  which,  there 
is  a ligament,  which,  lying  in  the  ham,  upon  the  back  part 
of  the  capsule,  is  named,  in  compliment  to  Winslow,  liga- 
MENTim  posTiGUM  WiNSLowH.  It  is  a ligament  somewhat 


304 


JOINTS  OF  THE 


resembling  the  lateral  ligaments  of  the  elbow.  It  arises  from 
the  outer  condyle,  goes  obliquely  across  the  back  part  of  the 
joint,  adheres  to  it,  and  strengthens  it ; but  often  it  is  not 
found  at  all,  or  in  such  straggling  fibres  as  cannot  be  account- 
ed a ligament.*  It  is  manifest  that  the  knee  requires  some 
such  additional  ligaments  behind,  to  serve  as  a check,  and  to 
prevent  its  yielding  too  far. 

2.  The  knee,  as  being  a hinge-joint,  has  strong  ligaments 
at  the  sides,  and  here  the  lateral  ligaments  are  particularly 
distinct,  and  can  be  raised  from  the  capsule ; on  the  inner 
side  of  the  joint,  there  comes  down  from  the  internal  con- 
dyle of  the  thigh-bone,  a broad  fiat  ligament,  which  is  fixed 
into  the  inner  head  of  the  tibia,  and  is  named  the  internal  lateral 
ligament ; on  the  outside  of  the  knee,  there  descends  from 
the  tip  of  the  outer  condyle  a much  stronger  ligament,  not 
quite  so  flat,  rather  round  : it  extends  from  the  condyle  of  the 
thigh-bone  to  the  bump  of  the  fibula  which  it  embraces.  It 
is  a little  conical  from  above  downwards;  it  is  from  two  to 
three  inches  in  length,  and  is  named  ligamentum  laterale 
EXTEKNUM  JLONGIOK,  to  distinguish  it  from  the  next;  for  be- 
hind this  first  external  ligament,  there  arises  a little  lower  from 
the  same  condyle,  along  the  outer  head  of  the  gastrocnemius 
muscle,  a ligament  which  is  called  the  ligamentum  laterale 
EXTERNUM  BREvioR,  and  it  is  not  shorter  only,  but  so  sparse 
as  not  to  be  easily  distinguished,  not  having  the  true  form  of 
a lateral  ligament  coming  down  from  the  condyle,  but  of  a 
mere  strengthening  of  the  capsule,  coming  upwards  from  the 
knob  of  the  fibula.f 

3.  The  joint  is  still  further  secured  by  internal  ligaments 
which  are  within  the  cavity  of  the  joint ; they  are  named  the 
CRUCIAL  LIGAMENTS  of  the  knee.  They  arise  betwixt  the 
hollow  of  the  condyles  of  the  thigh-bone,  and  are  implanted 
into  the  back  part  of  the  middle  rising  of  the  tibia : they  lie 
in  the  back  part  of  tbe  joint,  flat  upon  the  back  of  the  cap- 
sule, and  the  one  crossing  a tittle  before  the  other  (but  yet  in 
contact  with  each  other,  at  the  place  of  crossing ;)  they  are 
distinguished  by  the  names  of  anterior  and  posterior  cru- 
cial LIGAMENTS. 

The  POSTERIOR  CRUCIAL  ligament  is  more  perpendicular; 
it  arises  from  the  hollow  betwixt  the  condyles  of  the  thigh- 
bone, and  is  implanted  into  a roughness  on  the  back  of  the 
tibia,  betwixt  its  two  cup-like  hollows,  and  behind  the  tubercle 
which  divides  these  hollows  from  each  other.  While  the 

* Often  it  is  irregular,  or  in  straggling  fibres ; but  I have  never  found  it  wanting. 

I Some  strong,  but  irregular  accessory  ligameDts  go  down  to  that  part  of  the  head  of 
the  tibia  which  is  before  the  head  of  the  fibula. 


THIGH,  LEG,  AND  ANKLE. 


305 


posterior  arises  rather  from  the  internal  condyle,  the  anteri- 
or LIGAMENT  arises  properly  from  the  external  condyle,  passes 
obliquely  over  the  tuber,  in  the  articulating  surface  of  the 
tibia,  and  terminates  in  the  cup-like  hollow.  The  effect  of 
these  two  ligaments  is  more  particular  than  is  commonly  ob- 
served ; for  the  one  goes  obliquely  out  over  the  articulating 
surface  of  the  tibia,  while  the  other  goes  directly  down  behind 
the  joint ; and  of  course  when  the  knee  is  bended,  the  poste- 
rior ligament  is  extended ; when  the  leg  is  stretched  out,  the 
anterior  ligament  is  extended  ; they  both  are  checks  upon  the 
motions  of  the  joint : the  anterior  ligament  prevents  the  leg 
going  too  far  forwards,  the  posterior  ligament  prevents  its  be- 
ing too  much  bent  back  upon  the  thigh.* 

4.  The  most  admirable  part  of  the  mechanism  of  this  joint, 
is  the  two  SEMILUNAR  CARTILAGES.  They  are  so  named  from 
their  semilunar  form  : they  lie  upon  the  top  of  the  tibia,  so 
as  to  fill  up  each  of  them  one  of  the  hollows  on  the  top  of 
that  bone.  They  are  thicker  towards  their  convex  edges,  thin- 
ner towards  their  concave  edges  ; they  end  by  two  very  acute 
and  long  horns,  named  the  cornua  of  the  lunated  cartilages. 
In  short,  they  resemble  the  shape  of  the  label  which  we  put 
round  a wine  decanter ; and  the  two  horns  are  tied  to  the 
tubercle,  or  ridge  that  stands  in  the  middle  of  the  articular 
surface  of  the  tibia,  and  consequently  they  are  turned  towards 
each  other,  so  as  to  touch  in  their  points.  There  are  here,  as 
in  the  other  joints,  masses  of  fat  enclosing  the  fimbriated  ends 
of  the  mucuos  ducts.  These  fimbria;,  and  fatty  bundles,  are 
formed  chiefly  round  the  circumference  of  the  patella,  common- 
ly surrounding  it  with  a complete  fringe  ; they  are  also  found  at 
the  back  of  the  cavity,  about  the  crucial  ligaments,  and  in  all 
the  interstices  of  the  joint ; the  fatty  bundles  filling  up  the 
interstices,  protecting  the  mucous  ducts  from  more  violence 
than  what  is  just  necessary  to  empty  them,  and  perhaps  mix- 
ing their  exudation  with  the  mucus  of  the  ducts. 

These  masses  of  fat  lie  covered  by  the  delicate  internal 
surface  of  the  capsule,  and  the  mucous  fimbriae  project  from  it. 

The  inner  surface  of  the  capsule  is  so  much  larger  than  the 
joint  which  it  lines,  that  it  makes  many  folds  or  lurks,  and  se- 
veral of  these  are  distinguished  by  particular  names.  Thus, 
at  each  side  of  the  patella  there  are  two  such  folds,  the  one 

* Tliere  is  not  attention  enough  paid  to  tlie  origins  of  these  ligaments  from  the  femur  :, 
for  it  is  tile  origin  from  tlie  thigh-bone  whicli  determines  their  operation.  The  posterior 
ligament  com'es  from  the  root  of  the  internal  condyle,  and  depth  of  tlie  semilunar  notch, 
anterior  to  tiie  centre  of  motion  of  the  lower  head  of  the  femur  on  the  tibia  ; it  is  conse- 
quently strctclied  in  extending  the  leg.  Tiie  anterior  ligament  arises  from  tlie  root  of  the 
external  cop,dyle,,posterior  to  tiie  centre  of  motion  ; it  is  coasequently  sfiretchcd  is  the 
flexion  of  tlie  knee-joint. 


VOL.  I. 


306 


JOINTS  OF  THE 


larger  than  the  other,  whence  they  are  named  licamentuha 

ALAKE  MAJUS,  and  LIGAMENTUM  ALARE  MINDS.  TheSe  tWO 
folds  are  like  two  legs,  which  join  and  form  one  middle  fold, 
which  runs  across  in  the  very  centre  of  the  joint,  viz.  from  the 
lower  end  of  the  patella  to  the  point  of  the  thigh-bone,  in 
the  middle  betwixt  the  condyles.  It  keeps  the  looser  fatty 
bundles  and  fimbriated  ducts  in  their  place,  (viz.  the  hollow 
betwixt  the  condyles,  where  they  are  least  exposed  to  harm ;) 
thence  it  has  been  long  named  the  ligamentum  mucosum. 
The  internal  membrane  of  the  joint  covers  also  the  semilunar 
ligaments,  as  a perichondrium  ; it  comes  off  from  the  ridge  of 
the  tibia,  touches  the  horns  of  the  semilunar  cartilages,  moves 
over  the  cartilage,  so  as  to  give  them  their  coat,  and  at  the 
point  where  it  first  touches  the  horns,  it  forms  four  little  liga- 
ments, two  for  the  horns  of  each  cartilage.  These  tags  by 
which  the  four  points  of  the  lunated  cartilages  are  tied,  are 
named  the  ligamenta  caktilaginum  lunatacum,  or  more 
simply  named  the  four  adhesions  of  the  lunated  cartilages. 
There  is  a little  slip  of  ligament,  which  goes  round  upon  the 
forepart  of  the  knob  of  the  tibia,  and  ties  the  foreparts  of 
these  two  cartilages  to  each  other.  It  is  named  ligamentdm: 
TRANsvERSALB  COMMUNE,  because  it  gocs  across  from  the  fore 
edge  of  the  one  cartilage  to  the  fore  edge  of  the  other,  and 
because  it  belongs  equally  to  each ; but  for  their  further  se- 
curity, these  cartilages  also  adhere  to  their  outer  circle,  or 
thick  edge,  to  the  internal  surface  of  the  general  capsule  of 
the  joint  by  the  ligamentum  coronarium,  and  that  again  ad- 
heres to  the  lateral  ligaments  which  are  without  it;  so  that 
there  is  every  security  for  these  cartilages  being  firm  enough 
in  their  places,  to  bear  the  motions  of  the  joint,  and  yet  loose 
enough  to  follow  them  easily. 

This  joint  has  the  largest  burs:e  mucosae  of  all,  and  these 
perhaps  the  most  frequently  diseased.  There  is  one  bursa 
above  the  patella,  betwixt  the  common  tendon  of  the  ex- 
tensor muscles  and  the  forepart  of  the  thigh-bone,  which  is  no 
less  than  three  inches  in  length.  There  is  a smaller  bursa 
about  an  inch  below  the  patella,  and  under  the  ligament  of 
the  patella,  protecting  it  from  friction,  upon  the  head  of  the 
tibia.  These  .bursaj,  I am  persuaded,  are  often  the  seat  of 
disease  when  it  is  judged  to  be  in  the  joint  itself.  But  the 
truth  is  very  easily  known  ; for  if  a swelling  appear  under  the 
patella,  projecting  at  the  s;des,  and  raising  the  patella  from 
the  other  bones,  we  are  sure  that  it  must  be  in  the  main  cavity 
of  the  joint : but  if  swellings  appear  above  and  below  the  pa- 
tella, then  there  is  reason  to  believe  that  these  belong  to  the 
great  bursae,  which  are  placed  above  and  below  the  patella,  a 


THIGH,  LEG,  AND  ANKLE» 


307 


oojiiplaint  which  is  far  less  formidable  than  a swelling  of  the 
joint  itself:  I would  almost  say,  easily  cured  ; for  openings 
into  these  bursas,  though  they  should  be  avoided,  are  less 
dangerous  than  openings  into  the  joint.  It  is  from  mistaking 
such  tumours  for  collections  in  the  capsule  itself,  that  authors 
speak  of  openings  into  the  joint  as  a familiar  or  easy  thing,  or 
think  that  they  have  done  such  operations  safely,  when  pro- 
bably they  were  puncturing  the  bursae  only.* 

These  bursae  mucosae  lie  under  the  tendon  of  the  extensor 
muscles,  and  under  the  ligament  of  the  patella  : they  are  of 
the  same  substance  with  the  capsule  of  the  joint  itself:  they 
lie  over  the  capsule,  united  to  it  by  cellular  substance,  and 
the  bundles  of  fat  which  are  disposed  irregulairly  about  the 
joint,  belong  partly  to  the  bursse  and  partly  to  the  capsule  ; 
one  end  projecting  into  the  cavity  of  the  bursae,  while  the 
other  end  of  the  same  fatty  bundles  projects  into  the  cavity 
of  the  joint. 

Thus  the  knee-joint,  which  is  the  most  important  in  all  the 
body  ; the  most  oppressed  by  the  weight  of  the  trunk,  and  by 
the  accidental  loads  which  we  carry ; the  most  exercised  in 
the  common  motions  of  the  body,  and  the  most  liable  to 
shocks  and  blows,  which  is  the  most  superBcial  and  the 
weakest  in  all  that  respects  its  bones,  is  the  strongest  in  its 
ligaments,  and  the  most  perfect  in  all  the  provisions  for  easy 
motion. 

1.  The  great  capsule  of  the  joint  encloses  the  heads  of  the 
bone,  secretes  (in  part)  and  contaihs  the  synovia : lines  the 
joint  with  a smooth  and  delicate  membrane,  and,  by  turning 
over  all  the  parts,  and  adhering  to  them,  it  forms  the  peri- 
chondrium for  the  cartilaginous  heads  of  the  bones,  and  the 
covering  and  ligaments  for  the  moving  cartilages  of  the 
joint. 

2.  This  capsule,  which  is  exquisitely  thin,  and  which  was 
formed  for  other  uses  than  for  giving  strength  to  the  joint,  is 
surrounded  on  all  sides  with  such  continuations  of  the  common 
fascia,  and  such  particular  expansions  of  the  ham-string  and 
other  muscles,  as  by  adding  outwardly  successive  layers  to  the 
capsule,  brings  it  to  a considerable  degree  of  strength. 

3.  The  capsule  having  no  stress  upon  its  forepart,  is  very 
thin  upon  its  forepart,  viz.  at  the  sides  of  the  patella,  but  is 
strengthened  at  the  sides  by  fair  and  distinct  ligaments,  going 
from  point  to  point  of  the  three  great  bones,  and  so  large  and 
particular  as  to  deserve,  more  than  any  others  in  the  body, 

f 1 believe  that  the  great  bursae  and  the  joint  always  communicate  largely ; and  that 
being  consequently  one  continnous  surface,  the  opening  of  the  bars*  would  be  highly  im- 
proper. 


JOINTS  OF  THE 


tl08 

the  name  of  lateral  ligaments  ; at  the  back  part  of  the 
joint,  the  same  strength  is  not  required  as  at  the  sides ; yet  it 
must  be  stronger  than  at  its  forepart,  wherefore  it  is  strength- 
ened by  the  additional  bands  which  are  sometimes  general  and 
confused,  but  often  so  perfect  and  distinct,  as  to  be  known  by 
the  name  of  the  posterior  ligament  of  Winslow;  and  as 
the  lateral  ligaments  prevent  all  lateral  motions,  this  strength- 
ening of  the  capsule  serves  as  a check-band  behind. 

4.  It  is  only  in  the  greatest  joints  that  we  find  the  additional 
security  of  internal  ligaments,  and  the  only  joints  where 
they  are  perfect,  are  the  joints  of  the  hip  and  of  the  knee  ; 
the  former  having  its  round,  or  rather  triangular  ligament, 
which  secures  the  great  ball  of  the  thigh-bone,  and  fixes  it  in 
its  place ; the  latter  having  its  crucial  ligaments,  which, 
coming  both  from  one  point  nearly,  and  going  the  one  over 
the  face  of  the  tibia,  and  the  other  down  the  back  of  that 
bone,  serve  the  double  purpose  of  binding  the  bones  firmly 
together,  and  of  checking  the  larger  and  dangerous  motions 
of  the  joint,  the  fore  ligament  preventing  it  going  too  far  for- 
wards, and  the  back  ligament  preventing  it  bending  too  much. 

5.  A MOVING  cartilage  for  facilitating  motion  and  lessen- 
ing friction  is  not  common,  but  is  peculiar  to  those  joints 
whose  motions  are  very  frequent,  or  which  move  under  a 
greater  weight ; such  are  the  inner  head  of  the  clavicle,  the 
articulation  of  the  jaw,  and  the  joints  of  the  wrist  and  of  the 
knee  ; and  it  is  in  the  knee  that  the  moveable  cartilages  have 
their  most  perfect  forms  and  use,  are  large  and  flat  semilunar, 
to  correspond  with  the  forms  on  the  head  of  the  tibia  ; thicker 
at  their  outer  edges  to  deepen  the  socket;  and  though  move- 
able,  yet  so  tied  with  ligaments,  as  never  to  go  out  from  their 
right  place. 

And,  6.  The  mucous  folicular  bundles  of  fat,  and  the 
bursas  mucosae,  which  complete  the  lubricating  apparatus  of 
the  joint,  and  the  mucous  frenulas  or  ligaments,  which  both 
conduct  the  mucous  fringes  and  keep  them  in  their  place,  are 
more  perfect  in  the  knee,  and  greater  in  number  and  size, 
than  in  any  other  joint. 

I may  well  call  this  the  most  complicated,  and  (by  daily 
and  melancholy  proofs)  it  is  known  to  be  the  most  delicate 
joint  of  the  body. 

fibula. 

The  FIBULA  is  a support  to  the  tibia  in  its  various  accidents ; 
it  gives  a broader  origin  to  the  muscles,  and  it  is  the  chief 
defence  of  the  ankle-joint.  It  has  no  motion  upon  the  tibia; 


THIGH,  LEG,  AND  ANKLE.  309 

the  best  authors  speak  of  it  as  a symphysis,  which  classes  it 
with  the  joinings  of  the  pelvis,  and  excludes  it  from  the  list 
of  true  and  moveable  joints.  It  is  united  with  the  tibia  by  a 
sort  of  flat  cartilaginous  surface  upon  either  bone ; it  is  merely 
laid  upon  the  tibia,  not  sunk  into  it.  It  is  tied  by  a close  cap- 
sule : it  has  no  particular  ligament  for  itself ; but  is  strengtli- 
ened  by  the  external  lateral  ligament  of  the  knee,  which  ad- 
heres to  this  knob,  and  by  the  insertion  of  the  biceps  tendon, 
which  is  implanted  into  this  point,  and  which  spreads  its 
expanded  tendon  over  the  forepart  of  the  tibia,  and  holds  the 
bones  together ; and  the  firmness  of  the  fibula  is  further 
secured  by  the  great  interosseous  ligament,  w^hich  goes  from 
bone  to  bone.  Towards  the  head  of  the  bones  the  interos- 
seous ligament  is  deficient. 


ANKLE. 

The  ANKLE-JOINT  owes  less  of  its  strength  to  ligaments  than 
to  the  particular  forms  of  its  bones ; for  while  the  strong-lateral 
ligaments  of  the  knee  guard  it  so  that  it  cannot  be  dislocated 
till  they  are  torn,  the  lower  heads  of  the  tibia  and  fibula  so 
guard  the  foot,  that  when  luxated,  these  bones  are  often  broken. 
First,  the  fibula  is  so  connected  with  the  tibia,  at  its  lower 
end,  that  they  form  together  one  cavity  for  receiving  the  as- 
tragalus, with  two  projecting  points,  the  fibula  forming  the 
outer  ankle,  and  the  tibia  forming  the  process  of  the  inner 
ankle  ; the  joining  of  the  fibula  to  the  tibia  here,  is  like  that 
of  its  upper  end,  too  close  to  admit  of  the  smallest  motion, 
and  it  is  thoroughly  secured  by  particular  ligaments,  one  of 
which  passing  from  the  fibula  to  the  tibia  on  the  forepart,  is 
named  the  ligamentum  superius  anticum,  consisting,  in 
general,  of  one  or  two  distinct  flat  bands.  Another  more  con- 
tinued and  broader  ligamentous  membrane  goes  from  the 
fibula  to  the  tibia  across  the  back  part,  and  is  named  liga- 
mentum posTicuM  SUPERIUS ; the  ligamentum  posticum  in- 
EERius,  being  but  a slip  of  the  same.  Next  comes  the  cap- 
sule of  the  joint,  which  joins  the  astragalus  to  the  lower  heads 
of  the  tibia  and  fibula ; it  is  thinner  both  before  and  behind, 
than  we  should  expect  from  the  strength  of  a joint  which 
bears  all  the  weight,  and  the  most  violent  motions  of  the  body. 
But,  in  fact,  the  capsule  every  where  serves  other  purposes 
than  giving  strength  to  the  joint,  and  never  is  strong,  except 
by  additional  ligaments  from  without ; so  it  is  with  the  ankle- 
joint,  the  capsule  of  which  is  exceedingly  thin  before  ; but  it 
is  strengthened  at  the  back  part,  and  especially  at  the  sides,  by 


^10  .iOlNTS  OF  THE 

supplementary  ligaments:  First,  a strong  ligament  comes 
down  from  the  acute  point  of  the  inner  ankle,  expands  in  a 
radiated  form  upon  the  general  capsule  ; adheres  to  it,  and 
strengthens  it,  and  is  fixed  all  along  the  sides  of  the  astragalus 
to  the  os  calcis  and  naviculare.  This  ligament,  coming  from 
one  point,  and  expanding  to  be  inserted  into  a long  line,  has 
a triangular  form,  whence  itis  named  ligamentum  deltoides; 
and  while  the  general  ligament  secures  the  joint  towards  that 
side,  the  oblique  fibres  of  its  fore  edge  prevent  the  foot  being 
too  much  extended,  as  in  leaping,  and  its  oblique  fibres  on  the 
back  edge  prevent  its  being  too  much  bended,  as  in  climbing  ; 
but  the  ligaments  of  the  outer  ankle,  tying  it  to  the  outer  side 
of  the  astragalus,  are  indeed  distinct,  one  going  forwards,  one 
going  backwards,  and  one  running  directly  downwards ; one 
goes  from  the  point  or  knob  of  the  fibula,  obliquely  down- 
wards and  forwards  to  be  inserted  into  the  side  of  the  astra- 
galus ; it  is  square  and  flat,  of  considerable  breadth  and 
strength,  and  is  called  ligamem'um  fibulae  anterius.  Ano- 
ther ligament  goes  perpendicularly  downwards,  from  the  acute 
point  of  the  outer  ankle,  to  spread  upon  the  side  of  the  as- 
tragalus, and  of  the  capsule,  and  is  finally  inserted  into  the 
heel-bone  ; this  is  named  the  ligamentum  fibul®  perpen- 
DicuLARE.  A third  ligament  goes  out  still  from  the  same 
point,  to  go  backwards  over  the  back  part  of  the  capsule,  ad- 
heres to  the  back  of  the  capsule,  and  strengthens  it,  and  is 
named  ligamentum  inter  fibulam  et  astragalum  pos- 
TERius.  There  is  nothing  very  particularly  worthy  of  notice 
in  the  ankle-joint,  for  it  is  covered  with  cartilages,  lined  with 
a soft  and  mucous  membrane,  and  lubricated  with  mucous 
fimbria)  and  masses  of  fat,  such  as  are  found  in  all  the  joints. 
It  is  stronger  than  the  other  joints;  it  can  hardly  be  luxated, 
without  a laceration  of  its  ligaments,  and  breaking  of  the 
bones  which  guard  it  at  either  side ; and  it  is  the  great  vio- 
lence which  is  required  for  completing,  this  dislocation,  and 
the  terrible  complication  of  dislocation,  fracture,  and  lace- 
ration of  the  skin,  which  makes  this  accident  so  dangerous 
beyond  any  other  luxation. 


UNION  BETWIXT  THE  BONES  OF  THE  TARSUS. 

The  ASTRAGALUS,  OS  CALCIS,  OS  NAVICULARE,  and  all  the 
bones  of  the  tarsus,  are  united  to  each  other  by  large  heads, 
and  have  distinct  and  peculiar  joints;  besides  which,  the  bones 
are  cross-tied  to  one  another  by  ligaments,  so  numerous  and 
c'omplicated,  that  they  cannot  nor  need  not  be  explained. 


THIGH,  LEG,  AND  ANKLE. 


311 


They  pass  across  from  bone  to  bone,  in  an  infinite  variety  of 
directions,  some  longitudinal,  some  transverse,  and  some  ob- 
lique. There  is  a curious  complication,  which  we  may  call  a 
web  of  ligaments,  covering  either  side  of  the  foot  with 
shining  and  star-like  bundles  ; each  bone  has  its  capsular  liga- 
ments for  joining  it  to  the  next ; each  joint  of  each  bone  has 
its  articulating  cartilages  always  fresh  and  lubricated ; each 
joint  has,  besides  its  capsule,  flat  strips  of  oblique,  longitu- 
dinal, and  transverse  ligaments,  joining  it  to  the  nearest  bones, 
and  the  greater  bones  have  larger  and  more  important  liga- 
ments ; as  from  the  astragalus  to  the  os  calcis,  from  the  os 
calcis  to  the  os  naviculare,  and  from  that  again  to  the  sca- 
phoid bone,  &c. 

The  metatarsal  bones  have  their  capsular  ligaments  joining 
them  to  the  tarsal  bones,  and  they  have  ligaments  strength- 
ening their  capsules,  and  tying  them  more  strongly  to  the 
tarsal  bones ; and,  as  in  the  metacarpal  bones,  the  several 
ranks., are  tied  one  to  another  by  cross  ligaments  which  pass 
from  the  root  of  one  bone  to  the  root  of  the  next  ; so  we  have 
ligaments  of  the  same  description  and  use,  holding  the  meta- 
tarsal bones  together,  both  on  the  upper  and  on  the  lower  sur- 
face of  the  foot ; and  all  the  ligaments  of  the  foot  are  of 
great  strength  and  thickness.  The  lower  ends  of  the  meta- 
tarsal bones  have  also  transverse  ligaments  by  which  they  are 
tied  to  each  other.  The  toes  have  hinge-joints  formed  by 
capsules,  and  secured  by  lateral  ligaments,  as  those  of  the 
fingers  are ; and,  except  in  the  strength  or  number  of  liga- 
ments, the  joinings  of  the  carpus,  metacarpus,  and  fingers, 
exactly  resemble  the  joinings  of  the  tarsus,  metatarsus,  and 
toes. 

But  these  ligaments,  though  helping  to  join  the  individual 
bones,  could  not  have  much  eflect  in  supporting  the  whole 
arch  of  the  foot.  It  is  further  secured  by  a great  ligament, 
which  extends  in  one  triangular  and  flat  plate,  from  the  point 
of  the  heel  to  the  roots  of  each  toe.  This  is  named  the 
APONEUROSIS  PLANTARis  PEDIS,  which  is  not  merely  an 
aponeurosis  for  covering,  defending,  and  supporting  the 
muscles  of  the  foot ; that  might  have  been  done  on  easier 
terms  with  a fascia,  very  slight  compared  with  this  ; but  the 
chief  use  of  the  plantar  aponeurosis  is  in  supporting  the  arch 
of  the  foot.  It  passes  from  point  to  point,  like  the  bow- string 
betwixt  the  two  horns  of  a bow,  and,  after  leaping,  or  hard 
walking,  it  is  in  the  sole  of  the  foot  that  we  feel  the  straining 
and  pain ; so  that,  like  the  palmar  aponeurosis,  it  supports 
the  arch,  gives  origin  to  the  short  muscles  of  the  toes,  braces 
them  in  their  action,  and  makes  bridges  under  which  the  long 


312 


JOINTS  OF  THE 


tendons  are  allowed  to  pass : it  comes  olf  from  the  heel  in 
one  point ; it  grows  broader  in  the  same  proportion  as  the  sole 
of  the  foot  grows  broad.  It  is  divided  into  three  narrow 
heads,  which  make  forks,  and  are  inserted  into  the  roots  of 
the  second,  third,  and  fourth  toes ; and  the  great  toe  and  the 
little  toe  have  two  smaller  or  lateral  aponeurosis,  which  cover 
their  own  particular  muscles,  and  are  implanted  into  the  roots 
of  the  great  toe  and  of  the  little  toe. 

The  bursce  mucosas  surround  the  ankle  and  foot  in  great 
numbers.  None  of  them  having  any  very  direct  connection 
with  the  joint,  and  most  of  them  accompanying  the  long  ten- 
dons as  tliey  pass  behind  the  ankle,  or  in  the  sole  of  the  foot, 
are  of  that  kind  which  we  call  tendinous  sheaths.  First,  there 
are  sheaths  of  two  or  three  inches  long,  which  surround  the 
tendons  of  the  tibialis  posticus,  and  of  the  peronasi  muscles, 
as  they  pass  down  behind  the  ankle.  The  sheaths  of  the  pe- 
ronaei  begin  from  that  point  where  the  tendons  first  begin  to 
rub  against  the  bone,  and  are  continued  quite  down  into  the 
sole  of  the  foot ; making  first  a common  sheath  for  both  ten- 
dons, and  then  a bursa  peculiar  to  the  tendons  of  the  peronaeus 
brevis  muscle,  and  about  an  inch  in  length.  When  the  pero- 
nasus  longus  begins  to  pass  under  the  sole  of  the  foot,  the 
sheath  which  enclosed  it  behind  the  ankle  is  shut,  and  a new 
bursa  begins ; in  the  same  manner  where  the  tendons  of  the 
flexor  pollicis,  and  flexor  digitorum  pedis,  pass  behind  the 
inner  ankle,  a bursa  of  three  inches  in  length  surrounds  them, 
and  facilitates  the  motion.  As  the  tendons  of  the  flexor 
muscles  go  under  the  arch  of  the  foot,  they  lie  among  soft 
parts,  and  rub  chiefly  against  the  flesh  of  the  massa  carnea, 
and  the  belly  of  the  short  flexor  muscles  : but  whenever  they 
touch  the  first  joints  of  their  toes,  they  once  more  rub  against 
a hard  bone.  New  bursfe  are  formed  for  the  tendons ; each 
bursa  is  a distinct  bag,  running  along  the  flat  face  of  the  toe, 
and  is  of  a long  shape,  and  the  tendon  is  carried  through  the 
centre  of  the  lubricated  bag,  so  that  we  see  once  more,  that 
there  is  no  true  distinction  betwixt  bursfe  mucosas  and  ten- 
dinous sheaths ; nor  betwixt  the  tendinous  sheaths  and  the 
capsules  of  joints. 

Joints  have  been  arranged  under  various  forms,  but  not  with 
much  success;  and  I do  not  know  that  enumerating  the  joints 
in  any  particular  order  will  either  explain  the  motions  of  in- 
dividual joints,  or  assist  in  recording  their  various  forms ; 
some  joints  are  loose  and  free,  capable  of  easy  motions,  but 
weak  in  proportion,  and  liable  to  be  displaced  ; such  is  the 
JOINT  of  the  SHOULDER,  which  rolls  in  every  direction  ; other 
rolling  joints,  more  limited  in  their  motions,  are  better  secured 


THIGH,  LEG,  AND  ANKLE. 


313 


with  ligaments  of  peculiar  strength ; such  is  the  joiiw  of  the 
HIP,  where  the  ligaments  are  of  great  strength  both  within 
and  without;  some  wanting  all  circular  motions,  are  hinge- 
joints,  by  the  mere  form  of  their  bones  ; such  are  the  low'er 
JAW,  the  VERTEBRiE,  the  ELBOW,  and  the  ankle-joints  ; 
some  are  hinges  by  their  ligaments,  which  are  then  disposed 
only  along  the  sides  of  the  bones ; such  are  the  knee,  the 
RIBS,  the  fingers,  and  the  toes.  Sojne  joints  partake  of 
either  motion,  with  all  the  freedom  of  a ball  and  socket-joint, 
yet  with  the  strength  and  security  of  the  strictest  hinge : thus  the 
WRIST  having  one  joint  by  which  its  turning  motions  are 
performed,  and  another  joint  by  which  it  rolls,  has  the  two 
great  endowments  so  rarely  combined  in  any  joint  of  the 
freest  motion,  and  of  great  strength ; so  also  has  the  head, 
by  the  combination  of  two  joints  of  opposite  uses  and  forms  ; 
for  its  own  condyles  play  like  a mere  hinge  upon  the  atlas, 
and  the  axis  of  the  dentatus  secures  all  the  properties  of  a 
circular  joint ; this  combination  gives  it  all  the  motions  of 
either  joint,  without  their  peculiar  defects.  But  there  is  still 
a third  order  of  joints,  which  have  such  an  obscure  and 
shuffling  motion,  that  it  cannot  be  observed.  The  carpus  and 
METACARPUS,  the  TARSUS  and  metatarsus,  the  tibia  with 
the  fibula,  have  these  shuffling  and  almost  immoveable 
joints ; they  are  not  intended  for  much  motion  among  them- 
selves, but  are  appointed  by  a diffused  and  gradual  yielding, 
to  facilitate  the  motions  of  other  joints. 


VOL.  I. 


Rr 


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v'  jt  T^J.r  timostsrq'  wt-  oofflkt  I'fw^l'tOMiTii  ■.irmm 

■ynui  (mf  •fi^.:'-r.ifw>:  •■ 


THE 


OF  THE 


HEART  AND  ARTERIES. 


BOOK  L 


OP  THE  HEART. 


CHAP.  I. 


OF  THE  MECHANISM  OP  THE  HEART. 

The  heart  is  placed  nearly  in  the  centre  of  the  human 
body,  and  is  itself  the  centre  of  the  circulating  system.  The 
system  of  vessels  which  it  excites  and  moves,  consists  of  arte- 
ries and  of  veins  ; — the  arteries  act  with  great  strength,  with 
a pulsation  like  that  of  the  heart  itself,  and  convey  the  blood 
over  all  the  body  ; the  veins  are  in  greater  numbei’,  exceed- 
ingly large,  pellucid  almost  in  their  coats,  incapable  of  that 
energetic  action  with  which  all  the  functions  of  the  arteries 
are  performed  ; they  return  the  blood  to  the  heart  with  a slow, 
equable,  and  gentle  motion,  and  deposite  at  the  right  side  a 
quantity  of  blood  equal  to  that  which  is  at  each  pulsation 
driven  out  from  the  left.  The  heart  is  placed  betwixt  the  ar- 
teries and  the  veins,  to  regulate  and  enforce  their  action ; to 
2'eceive  the  blood  from  the  veins  by  a slow  dilatation,  and  to 
restore,  by  a sudden  contraction,  that  force  which  the  blood 
loses  in  passing  round  the  circle  of  the  body.  But  the  heart 
has  also  another  and  more  important  office  to  perform  : for  by 
having  four  great  cavities  and  two  orders  of  arteries,  it  per- 
forms in  the  same  instant  two  circulations,  one  for  the  lungs 
and  one  for  the  body  ; it  receives  from  the  lungs  nothing  but, 
pure  blood,  it  delivers  out  to  the  body  nothing  but  what  is  fit 
for  its  uses  : and  this  purifying  of  the  blood,  and  this  excite- 


316 


OF  THE  MECHANISM 


ment  of  the  arteries,  are  two  chief  points  of  modern  physio- 
logy,  which  every  step  of  the  following  demonstration  will 
tend  to  explain. 

It  will  be  most  easy  to  conceive  at  first  the  idea  of  a more 
simple  heart,  of  one  circle  of  actions,  of  one  simple  circu- 
lation ; of  one  bag  for  receiving,  and  another  joined  to  it  for 
propelling  the  blood-  Indeed  a heart  consists  merely  of  these 
essential  parts ; a great  vein,  an  auricle,  a ventricle,  and 
a great  artery  : of  a vein  which  returns  the  blood  from  all 
the  body ; of  an  auricle  or  smaller  bag,  which  receives  that 
blood  and  retains  it  till  the  action  of  the  heai’t  is  relaxed : of 
a ventricle  (which  is  the  proper  heart)  strong,  muscular,  very 
irritable,  and  easily  excited,  into  which  the  auricle  pours  its 
blood  ; of  an  artery  which  is  allied  to  the  ventricle  in  strength 
and  action,  (as  the  auricle  is  to  the  vein  in  the  delicacy  of  its 
coats,)  and  which  carries  on  the  blood  to  the  extremities  of 
the  body ; — and  the  vein  and  artery  meeting  at  their  extre- 
mities in  the  body,  and  uniting,  the  whole  is  a circle,  and  the 
heart  is  the  central  power. 

If  an  animal  do  not  breathe,  its  system  will  be  what  I have 
now  described ; it  will  have  but  one  vein,  one  auricle,  one 
ventricle,  one  artery  ; it  will  have  one  simple  heart : but  with 
us,  and  other  breathing  animals,  it  is  not  so  ; and  I am  now  to 
describe  a more  complex  and  curious  circulation.  For  sup- 
pose this  blood,  so  essential  to  our  existence,  to  have  in  it 
some  principle  of  life,  which  is  continually  lost,  or  in  its  pas- 
sage through  the  body,  to  be  impregnated  with  something 
which  should  be  thrown  off,  that  principle  must  be  continually 
renewed,  or  an  opportunity  given  to  send  off  what  is  offensive 
to  life  : the  heart  which  fills  the  arterial  system,  must  not  be 
taken  from  its  appointed  office,  nor  disturbed ; nature  appoints 
a second  heart,  which  belongs  entirely  to  this  most  important 
of  all  functions,  viz.  renewing  the  blood  ; and  it  may  be  re- 
newed in  many  various  ways.  It  might,  for  example,  circu- 
late in  some  peculiar  viscus,  like  the  liver  or  spleen ; in  the 
foetus  it  does  circulate  in  such  a mass,  for  the  placenta  is  a 
thick  and  flat  cake,  whose  office  we  know  to  be  equivalent  to 
that  of  the  lungs,  but  whose  structure  we  do  not  understand  : 
ill  the  chick  w'e  see  its  blood  circulating  over  the  yolk,  (for  the 
yolk  is  inclosed  within  the  membranes  of  the  unhatcbed 
chick,)  and  we  perceive  the  blood  redder  as  it  returns  to  the 
heart,  and  plainly  changed  : in  fish  we  find  the  blood  circu- 
lated over  the  gills,  exposed  thoroughly  to  the  water  in  which 
they  swim,  and  thus  the  gills  perform  to  them  the  function  of 
lungs.  But  in  all  breathing  creatures,  the  lungs  do  this  office  ; 
the  lungs  are,  next  to  the  heart  itself,  essential  to  life ; in  those 


OF  THE  HEART. 


31? 


who  die  from  bleeding,  we  can  perceive  from  the  livor  of  the 
face,  from  the  sobbing  and  struggles  of  the  chest,  from  the 
regular  convulsive  sighs  of  those  creatures  which  are  butchered, 
rather  a desire  for  air  than  a want  of  blood.  It  is  for  the  pur- 
pose  of  this  second  circulation  that  nature  has  appointed  in  all 
the  wai’m  blooded  animals  two  hearts,  a heart  for  the  lungs, 
and  a heart  for  the  body  ; two  veins,  two  auricles,  two  ventri- 
cles, and  two  great  arteries,  one  the  pulmonic  artery,  or  artery 
of  the  lungs,  the  other  the  aorta,  or  artery  of  the  body. 

There  are  other  varieties  which  distinguish  animals  into 
creatures  of  cold  or  of  warm  blood ; for  there  are  certain  con- 
stitutions which  do  not  require  that  the  blood  should  be  thus 
continually  renewed.  It  is  not  because  animals  are  amphi- 
bious, or  go  into  the  water,  that  they  have  peculiar  lungs; 
for  the  Land  Tortoise,  the  Newt,  the  Cameleon,  never  go 
into  the  water  ; yet  they  have  membranous  lungs  : nor  indeed 
can  the  amphibi.T,  as  the  Seal,  the  Porpoise,  the  Sea-Lion, 
&c.  dive  and  exist  under  water  more  than  a man  can  do, 
though  for  whole  days  they  lie  in  herds  basking  upon  the 
shore  : it  is  their  peculiar  constitution  to  need  less  than  other 
creatures  the  office  of  the  lungs.  The  cold-blooded  animals 
are  generally  creeping  animals,  sluggish,  languid,  cold,  inert, 
difficultly  moved,  and  tenacious  of  life  to  a wonderful  degree. 
They  can  bear  all  kinds  of  stimuli;  they  can  bear  to  have 
their  heads,  legs,  bowels,  cut  away ; and  among  other  pecu- 
liarities of  this  constitution,  they  can  live  long  without  air : 
they  will  rise  from  time  to  time  above  water,  if  you  allow 
them ; they  can  bear  again  to  be  kept  under  w ater,  if  you 
force  them  : but  if  they  can  live  long  under  w’ater,  they  can 
also  live  at  least  as  long  after  you  have  cut  off  their  heads,  or 
cut  out  their  hearts. 

Of  those  cold-blooded  creatures  always  either  the  heart  or 
the  arteries  are  peculiar  ; the  heart  is  so  in  many  amphibise, 
as  in  the  Turtle,  where  the  heart  seems  to  consist  of  three 
ventricles,  but  with  partitions  so  imperfect  betwixt  them  that 
they  are  absolutely  as  one  : this  one  ventricle  gives  out  both 
the  great  arteries  ; the  blood  of  the  lungs  and  the  blood  of 
the  body  are  both  mixed  in  the  heart : and  since  there  are  two 
arteries  conveying  this  mixed  blood,  if  the  two  arteries  be 
nearly  equal  in  size,  then  it  is  just  one  half  of  the  blood 
thrown  out  by  the  heart  at  each  stroke  that  receives  the  bene- 
fit of  the  lungs.  In  many  others,  as  the  frog,  the  newt,  the 
toad,  the  peculiarity  is  in  the  arteries  alone ; they  have  one 
single  and  beautiful  heart ; there  is  one  large  auricle  as  a re- 
servoir for  all  the  blood  both  of  the  body  and  of  the  lungs ; 
there  is  one  neat,  small,  and  very  powerful  ventricle  placed 


318 


OF  THE  MECHANISM 


below  the  reservoir,  having  strength  quite  sufficient  for  mov- 
ing both  the  blood  of  the  lungs  and  the  blood  of  the  body  ; and 
this  ventricle  gives  off  an  aorta,  which  soon  divides  into  two 
branches,  one  for  the  body,  and  one  for  the  lungs ; and  these 
of  course  have  but  half  the  blood  of  this  heart  exposed  to  the 
air  : these  also  are  cold-blooded  animals. 

But  all  breathing  creatures,  such  as  are  called  animals  of 
hot  blood,  have  two  hearts:  the  one  heart  is  sending  blood 
through  the  lungs,  while  the  other  heart  is  pushing  its  blood 
over  the  body  ; not  the  half  only,  but  the  whole  blood  which 
is  sent  by  each  stroke  of  the  heart  over  the  body  must  have 
first  passed  through  the  lungs ; no  blood  can  reach  the  heart  of 
the  body  which  has  not  been  sent  to  it  through  the  lungs ; or, 
in  other  words,  the  veins  of  the  lungs,  and  they  alone,  feed  the 
left  side  of  the  heart. 

Words  alone  will  never  explain  any  of  the  endless  difficul- 
ties which  concern  the  mechanism  of  the  heart;  but  at  every 
point,  in  every  kind  of  difficulty,  in  explaining  the  form,  the 
parts,  the  posture,  even  the  coats  or  coverings  of  the  heart,  I 
shall  have  recourse  to  plans,  such  as  cannot  fail  to  make  all 
this  intricate  mechanism  be  easily  conceived. 

The  most  simple  form  of  the  heart,  which  is  represented  in 
the  plan.  No.  1.  has  a vein  marked  (a,) — and  auricle  (6,) — a 
ventricle  (c,) — an  artery  {d ;) — it  has  no  provision  for  purify- 
ing the  blood ; it  has  no  resemblance  to  that  kind  of  heart 
which  is  connected  with  lungs ; but  the  blood  is  received  by 
the  vein,  falls  into  the  auricle,  is  driven  by  its  force  into  the 
ventricle,  by  the  ventricle  it  is  thrown  into  the  artery,  and 
courses  round  all  the  body,  till  at  length,  reaching  the  extremi- 
ties of  the  veins,  it  passes  by  the  veins  to  the  auricle  a second 
time,  and  so  this  single  circle  is  perfect. 

The  heart  of  the  amphibious  creature  is  represented  in  No. 
2. ; it  is  a frog’s  heart : it  has  the  most  simple  form,  and  the 
fewest  parts;  it  has  the  same  vein,  auricle,  ventricle,  and  ar- 
tery ; but  its  great  artery  divides  into  two  chief  branches,  of 
which  [d) — the  aorta  goes  to  the  body, — (e)  the  pulmonic  ar- 
tery goes  to  each  side  of  the  lungs. 

The  heart  of  a breathing  creature  is  represented  in  No.  3. 
in  its  most  intelligible  form  ; and  the  double  circulation  of  the 
human  body  may  be  traced  easily  in  the  following  way. — Here 
the  heart  of  the  lungs  is  set  off  from  the  heart  of  the  body, 
being  as  distinct  in  office  as  in  form  and  parts;  on  the  right 
side  is  the  heart  of  the  lungs,  on  the  left  side  is  the  heart  of 
the  body. — (a)  Is  the  great  vein  called  vena  cava  from  its  im- 
mense size  ; — there  is  an  ascending  and  a descending  cava  ; 
the  one  brings  the  blood  from  the  head  and  arras,  the  other 


VoI.E. 


.jYrn/j  /j/  ^//r  Yf/r/lZ 


Liin 


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N":i 


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F./^. 


t 


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.:,r- 


't,  ' ' ' ■■■  / 


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'■■■  •><:  ..  ■ ' 

h yi-’,  y^’yr\<:-  ' ■ ■ r-/:  ;v;  > f’U;  ydr-  "«•<;"  s '.i'. 

•!■;-■;  /•;■  t-jJ-  - '.■>  ' 

,,  B'lS  1-1 

' ’"s‘  ‘'‘-'  y'iiia  d ><*>  4*Mvjt  • ..  ;a 

'.fi;  .'•li'i  M:  ,:t 

■ ' > ■'■  'boft  fitfjluoyt'ne  \ j‘ . < ni lA 

i:,;  > ( I i o-v.»  if  <i  ..•\[j^#s.‘*  a.avsdi : y-  d' ' 

■>■';  jb-iisihif  8i  li.  :.*.  .•'4  ■>‘Ai’if(^  vf 

i dV'ff  ii.  aUii  (>liit  ,‘frinh '» 

r ■ (■.'?  tKi  irti'v-  ..■,,r  :.  : v.  IV, '.,'  i'  i?3  ■■  r.'^v. I ; 


OF  THE  HEART. 


319 


brings  the  blood  from  all  the  lower  parts  of  the  body  ; they 
meet  at  (a,)  and  form  by  their  dilatation  there,  a chief  part  of 
that  bag  which  is  called  the  auricle, — in  it  they  deposite  all 
the  returning  blood  of  the  body,  and  thus  present  it  at  the  right 
side  of  the  heart  to  be  moved  through  the  lungs. — (h)  Is  the 
right  sinus,  or  right  auricle  ; it  is  in  part  formed  by  a dila- 
tation of  these  veins,  but  it  puts  on  a strong  and  muscular  na- 
ture as  it  approaches  the  heart ; it  is  the  first  cavity  of  the 
heart,  and,  like  all  its  parts,  is  strong  and  irritable ; it  is  filled 
by  the  returning  blood  of  the  cavre ; it  receives,  dilates,  is  op- 
pressed by  this  great  quantity  of  blood  : it  is  strongly  excited 
to  act;  in  its  action  the  blood  goes  down  into  the  ventricle  or 
lower  cavity  of  the  heart. — (c)  Is  the  right  ventricle,  thick 
and  strong  in  its  walls,  and  of  great  muscular  power : it  is  filled 
by  the  auricle,  and  is  strongly  stimulated  both  by  the  stroke  of 
the  auricle,  and  by  the  weight  and  quantity,  and  also,  in  some 
degree,  by  the  qualities  of  the  blood  ; its  action  is  sudden  and 
violent,  and  it  drives  the  blood  through  all  the  system  of  the 
lungs.— (d)  Is  the  pulmonic  artery, — the  artery  of  the  lungs, 
which  receives  all  the  blood  of  the  right  side  of  the  heart;  it 
is  filled  by  the  stroke  of  the  right  ventricle,  from  whose  cavity 
it  arises ; it  carries  the  blood  in  many  branches  through  all  the 
substance  of  the  lungs ; and  thus  that  blood  which  had  returned 
imperfect  and  robbed  of  its  vital  quality  to  the  right  auricle  of 
the  heart,  is  by  this  circulation  through  the  pulmonic  artery 
ventilated  and  renewed,  and  made  fit  for  the  uses  of  the  sys- 
tem; and  thus  the  lesser  circulation,  or  the  circulation  of  the 
lungs,  the  circulation  of  the  right  side  of  the  heart  is  completed, 
and  the  purified  blood  is  brought  round  to  the  left  side  of  the 
heart  to  undergo  the  greater  circulation  or  the  circulation  of 
the  body. 

Thus  it  is  from  the  extremities  of  this  first  circle  that  the 
second  circle  begins ; it  consists  of  like  moving  powers,  of  an 
auricle,  ventricle,  vein,  and  artery ; for  as  the  right  heart  re- 
ceives the  contaminated  blood  of  the  body  from  the  veins  of 
the  body,  the  left  heart  receives  the  purified  blood  of  the  lungs 
from  the  veins  of  the  lungs. — (e)  Represents  the  veins  of  the 
LUNGS,  which  are  sometimes  three,  sometimes  four  in  number; 
two  enter  from  each  side  of  the  lungs,  and  return  the  blood  pu- 
rified in  the  lungs  to  the  left  auricle  of  the  heart. — (/)  Is  the 
LEFT  AURICLE,  Smaller,  but  more  muscular,  and  stronger  than 
the  right;  it  receives  easily  whatever  quantity  of  blood  the 
lungs  convey  to  it ; it  is  irritated,  contracts,  forces  the  mouth 
of  the  ventricle,  and  fills  it  with  this  purified  and  redder 
blood.-:— (^)  Is  the  left  ventricle,  whose  form  is  longer,  its 
fleshy  walls  thicker,  its  cavity  smaller,  its  power  greater  far 


320 


OF  THE  MECHANISM 


than  that  of  the  right  side  ; this  ventricle  is  thus  small  that  it 
may  he  easily  filled  and  stimulated,  and  thus  strong  that  it  may 
propel  all  the  blood  of  the  body. — (A)  Is  the  aoeta  or  great 
artery  of  the  body,  arising  from  this  left  ventricle,  just  as  the 
pulmonic  artery  arises  from  the  right : the  left  ventricle,  by  its 
strong  and  sudden  stroke,  not  only  delivers  itself  of  its  own 
blood,  but  propels  all  the  blood  of  the  body,  communicates 
its  vibratory  stroke  to  the  extremest  vessels,  and  excites  the 
whole ; this  is  the  greater  circle  or  circulation  of  the  body, 
as  opposed  to  the  shorter  circulation  or  lesser  circle  of  the 
lungs. 

That  there  are  strictly  two  hearts,  is  now  clearly  made  out ; 
they  are  different  in  office ; there  are  two  distinct  hearts,  two 
systems  of  vessels,  two  kinds  of  blood,  and  two  circulations. 
These  two  hearts  might  have  done  their  offices,  though  placed 
in  the  opposite  sides  of  the  breast;  it  is  in  order  to  strengthen 
mutually  the  effect  of  each  other  that  they  are  joined ; for  the- 
fibres  of  the  two  hearts  intermix ; they  are  both  inclosed  in  one 
membranous  capsule,  viz.  the  pericardium ; the  veins,  auri- 
cles, ventricles,  and  arteries,  correspond  in  time  and  action 
with  each  other,  and  harmonize  in  a very  beautiful  manner. 
But  this,  I believe,  will  be  more  easily  explained  by  marking 
the  succession  of  motions,  by  a suite  of  figures  placed  upon 
the  several  parts  of  the  heart,  by  which  the  successive  motions 
are  performed. 

In  No.  4.  I have  joined  the  right  and  left  hearts;  both  that 
it  may  be  seen  how  the  left  heart  locks  in  behind  the  right 
heart,  how  the  right  heart  comes  to  be  the  anterior  one,  and 
how  the  aorta  seems  to  arise  from  the  centre  of  the  heart  while 
its  root  is  covered  by  the  great  artery  of  the  lungs;  and  also 
that  the  synchronous  parts,  (i.  e.)  the  parts  which  beat  time  with 
each  other  may  be  correctly  seen. — 1.  The  cavas  are  receiv- 
ing the  blood  from  all  parts  of  the  body,  and  in  the  same  in- 
stant the  pulmonic  veins  are  receiving  blood  from  the  lungs. 
2.  The  BIGHT  AUBicnE  is  gradually  filling  with  the  contami- 
nated blood  of  the  body  ; the  left  auricle,  marked  also  with  a 
second  figure,  is  filling  with  purified  blood  from  the  lungs.  3. 
The  niGHT  VENTRICLE  is  stimulated  by  its  auricle,  and  throws 
its  contaminated  blood  into  the  lungs ; and  in  the  same  moment 
the  left  ventricle  throws  its  purified  blood  over  the  body.  4. 
The  PULMONIC  ARTERv  re-acts  upon  the  blood  driven  into  it 
by  the  heart;  and  in  the  same  moment  the  aorta  re-acts  upon 
the  blood  thrown  into  it,  and  that  re-action  works  it  through  all 
this  great  system  of  vessels  from  this  the  centre  to  all  the  ex- 
tremities of  the  body. 


OP  THE  HEART. 


321 


Thus  it  Is  easy  to  perceive  how  the  successive  actions  ac- 
company each  other  in  the  opposite  sides  of  the  heart : 1.  The 
two  veins  swell;  2.  The  two  auricles  are  excited;  3.  The 
two  ventricles  are  filled  with  blood ; 4.  The  two  arteries  take 
up  and  continue  this  pulsating  action  of  the  heart.  It  is  thus 
that  the  two  hearts  assist  and  support  the  actions  of  each  other, 
and  there  seems  almost  a physical  necessity  for  their  being 
joined ; yet  on  the  very  best  authority,  and  after  deliberate 
dissection,  we  are  entitled  to  affirm,  that  the  heart  is  found, 
not  with  its  apex  sharp  and  conical,  but  cleft ; the  two  ventri- 
cles plainly  distinct  from  each  other,  and  divided  by  a great 
space.  “Latro,  quse  poenas  scelerum  luebat,  quando  exente- 
raretur  a carnifice,  cor  habuit  singularis  figurae,  mucrone  non 
acuto,  ut  fieri  solet,  sed  bifido  ; ut  distinct!  ventriculi  raanifes- 
tius  externa  facie  apparuerint,  dexter  nempe  et  sinister,  inter- 
jecto  magno  hiatu,”* 

OF  THE  PARTS  OF  THE  HEART. 

As  yet  I have  explained  only  the  general  plan  of  the  circu- 
lation, without  having  described  those  curious  parts  which  are 
within  the  cavities  of  the  heart,  and  which  support  the  actions 
in  this  beautiful  harmony  and  perfect  order,  each  part  subordi- 
nate to  some  other  part,  and  each  action  succeeding  some 
other  action  with  perfect  correctness,  often  without  one  un- 
steady motion  or  alarming  pause,  during  the  course  of  a long 
irregular  life. 

1.  The  VEN^  CAVJE  are  two  in  number  ;f  they  are  named 
venae  cavae  from  their  very  great  size ; the  one  brings  the 
blood  from  the  upper,  and  the  other  from  the  lower  parts  of 
the  body,  and  they  are  formed  of  these  branches:  the  upper 
vena  cava  (a)  is  properly  termed  the  descending  cava,  be- 
cause it  carries  the  blood  of  the  head  and  arms  downwards  to 
the  heart : this  great  vein  is  properly  a continuation  of  the 
right  jugular  vein,  which  joins  with  the  right  axillary  vein, 
and  then  descends  into  the  chest  a great  trunk ; and  in  the 
upper  part  of  the  chest  it  is  joined  at  (6) — by  a great  branch, 
containing  tbe  axillary  and  jugular  veins  of  the  left  side,  wdiich, 
in  order  to  reach  the  cava,  crosses  the  upper  part  of  the  chest, 
and  lies  over  the  carotid  arteries.  The  lower  vena  cava,  or 

* Bartholini  Epist.  p.  170.  There  are  examples  in  the  lower  animals,  of  the  hearts 
%eing  actually  in  distinct  parts  of  the  System. 

f Let  the  reader  observe,  that  the  whole  of  this  description  of  the  various  parts  of  the 
heart  is,  as  it  were,  an  explanation  of  the  plans  No.  5.  and  6.  j of  which  tlie  No.  [>.  shows 
the  right  side  of  the  heart,  or  the  heart  of  the  lungs  opened ; while  No.  6.  shows  only  the 
left  heart,  or  the  heart  of  the  body  opened. 

vofc.  I.  S s 


322 


OF  THE  MECHAISISM 


CAVA  ASCENDENS,  brings  in  like  manner  all  the  blood  from  the 
belly  and  lower  parts  of  the  body  by  two  great  branches.  One, 
marked  (c,) — is  the  great  vein  which  lies  in  the  belly  along 
the  left  side  of  the  spine,  and  brings  the  blood  from  the  legs, 
the  pelvis,  and  parts  of  generation,  the  kidneys,  &ic. ; it  is 
named  the  vena  cav  a aboominalis,  because  of  its  lying  in  the 
abdomen.  Another,  marked  (ddd,) — arises  in  three  or  four 
great  branches  from  the  liver  ; it  is  named  the  branches  of  the 
vena  cava  in  the  liver,  or  the  vena  cava  uebatica  ; and  these 
two  make  up  the  lower  cava;  and  the  lower  and  the  upper  cavas 
now  join  themselves  at  (c,) — to  form  the  right  sinus  of  the  heart. 

2.  The  RIGHT  SINUS  of  THE  HEART,  marked  (e,)  is  of  con- 
siderable extent ; it  is  just  the  gradual  dilatation  of  the  two 
veins  forming  the  auricle  or  reservoir  which  is  incessantly  to 
supply  the  heart ; the  veins  grow  stronger  as  they  approach 
the  sinus,  and  the  sinus  still  stronger  as  it  approaches  the  auri- 
cle or  notched  and  pendulous  part  (/,)  and  the  auricle  again 
approaches  in  its  nature  to  the  ventricle  of  the  heart ; for  it  is 
crossed  with  very  strong  muscular  fibi-es,  which  make  veiy 
deep  risings  and  furrows  upon  its  inner  part.  To  say  that  these 
veins,  or  the  sinus  which  they  form,  are  not  muscular,  merely 
because  they  are  not  red  nor  fleshy,  is  very  ignorant;  for  the 
ureters,  arteries,  intestines,  the  iris,  and  many  other  parts  of  the 
human  body,  are,  at  the  same  time,  perfectly  muscular  and 
perfectly  pale  ; and  the  heart  of  a fish  is  as  transparent  as  a 
bubble  of  water,  and  yet  is  so  irritable  that  after  it  is  brought 
from  market,  if  you  lay  open  the  breast,  and  stimulate  the 
heart  with  any  sharp  point,  it  will  renew  its  contractions,  and 
in  some  degree  the  circulation. 

3.  The  TUBERCULUM  Loweri  should  be  looked  for  in  this 
point,  if  it  were  not  really  an  imagination  merely  of  that  cele- 
brated anatomist.  The  whole  matter  is  this  ; the  two  veins 
meet,  not  directly,  but  at  a considerable  angle  within  the  vein, 
as  at  (g).  Lower  conceived  a projection  of  the  inner  coats  of 
the  vein  at  this  point  much  more  considerable  than  what  I 
have  here  represented.  It  was  thought  to  do  the  office  of  a 
valve,  to  break  the  force  of  the  descending  blood,  to  defend 
from  pressure  that  blood  which  is  ascending  from  the  lower 
cava,  and  to  direct  the  blood  of  the  upper  cava  into  the  right 
auricle  of  the  heart.  But  there  is  no  such  thing;  although 
anatomists  were  at  one  time  so  fond  of  this  trivial  observation 
that  not  one  of  them  would  demonstrate  the  heart,  without 
demonstrating  the  tuberculum  Loweri;  whereas,  if  the  blood 
of  the  lower  cava  needs  any  screen  above  it  to  defend  it  from 
the  pressure,  it  is  (as  I shall  show  presently)  quite  of  another 
kind  ; and  in  the  place  appointed  for  finding  this  tuberculum 


OF  THE  HEART. 


S2.3 

Lower!  vve  can  find  nothing  but  on  the  inside  of  the  natural 
angle  of  the  two  veins,  and  on  the  outside  some  fat  cushioned 
up  in  that  angle  in  the  line  (A).  Though  generally  wanting,  I 
have  found  the  tuberculum  Loweri  very  distinct  in  the  hu- 
man heart. 

4.  The  AURICLE  is,  as  I have  said,  a small  appendix  to  the 
great  bag  or  sinus,  and  is  marked  (/).  It  is  small,  semi-circu- 
lar, notched  or  scolloped,  and  somewhat  like  a dog’s  ear  ; 
whence  its  name.  In  general,  we  name  the  whole  of  this  bag 
auricle ; but  by  this  plan  the  names  of  sinus  and  auricle  must 
be  easily  understood.  The  point  chiefly  to  be  noted  is  this, 
that  the  veins,  as  they  approach  the  auricle,  are  thin,  delicate, 
trans[)arent ; that  where  they  expand  into  the  sinus  they  be- 
come fleshy,  thick,  and  strong ; that  in  the  auricle  itself  the 
muscular  fibres  at  (/)  are  very  strong,  have  deep  sulci  like 
those  of  the  ventricle,  cross  each  other  so  as  to  make  a net- 
work; and  these  strong  fibres  (/)  are  what  are  named  the 
musculi  pectinati  auriculas.  Where  these  muscles  run,  as  in 
cords,  across  the  auricle,  they  are  very  thick  and  opaque ; but 
in  the  interstice  of  each  stripe  or  muscular  fibre,  the  auricle  is 
transparent,  like  the  membranes  of  the  veins ; and  these  stripes 
of  muscular  fibre  which  are  laid  upon  this  thin  membrane  are 
almost  as  regular  as  the  teeth  of  a comb ; and  thus  they  are 
named  musculi  pectinati. 

5.  The  VALVES  of  the  auricle  are  placed  at  the  circle  (i), 
where  the  auricle  enters  into  the  ventricle,  and  the  valves  ai’e 
marked  (A) ; and  how  necessary  these  are  for  regulating  the 

auricular  valves. 


AoRiruLAR  Valves  explained. 

Fig.  7.  shows  the  Auricle  and  Ventricle  cut  open,  and  the  valve  hanging  in  three  great 
divisions. — (a)  Part  of  the  inside  of  the  Auricle.-— (4)  Part  of  tlie  inside  of  the  Ventricle. — 
The  tendinous  Circle  from  which  the  membrane  of  the  valve  arises. — (d)  The  Columnse 
Carneas.— (e)  The  Cordae  Tendinece. — {^)  The  three  great  divisions  of  the  Valve. — 
No.  8.  shows  the  circle  of  the  entrance  of  the  Auricle  still  entire ; where — (g) — marks  the 
entrance  into  the  Auricle.— Aj55^)  The  tiiree  great  division?  of  the  Valve. — (d)  TheCo- 
lumna;  Carneae ; and-*(e)  The  Cordre  Tendinete. 


324 


OF  THE  MECHANISM 


movements  of  the  heart  will  be  easily  understood  by  consi- 
dering the  conditions  in  which  the  auricle  and  ventricle  act. 
First  the  cavie  pour  in  a flood  of  blood  upon  the  sinus  and 
auricle,  with  a continual  pressure  ; the  moment  the  auricle 
has  contracted  it  is  full  again  ; the  pressure  from  behind  ex- 
cites it  to  act,  and  while  it  is  acting  there  is  no  occasion  for 
valves  to  guard  those  veins  whose  blood  is  pressing  forwards 
continually,  because  they  are  continually  full,  and  have  be- 
hind them  the  whole  pressure  of  the  circulating  blood.  But 
when  the  auricle  acts,  it  throws  its  blood  into  the  ventricle, 
fills  it,  and  stimulates  it;  the  auricle  then  lies  quiescent  for 
a moment,  while  it  is  gradually  filling  from  behind  with  blood ; 
but  during  this  quiescent  state  the  whole  blood  from  the  ven- 
tricle would  rush  back  into  it,  were  it  not  guarded  by  valves. 
The  valves,  then,  whicb  rise  whenever  the  ventricle  begins 
to  act,  are  of  this  kind  : there  is,  first,  a tendinous  circle  or 
hole,  by  which  the  auricle  communicates  with  the  ventricle. 
The  opening  is  large  enough  to  admit  two  or  three  fingers  to 
pass  through  it ; it  is  smooth,  seems  tendinous,  is  plainly  the 
place  of  union  betwixt  the  auricle  and  ventricle,  which  are 
in  the  fcctus  (in  the  chick,  for  example,)  distinct  bags  ; and 
from  all  the  circle  of  this  hole  arises  a membrane,  thin,  and 
apparently  delicate,  but  really  very  strong ; not  divided  into 
particular  valves  at  this  root  or  basis,  but  as  the  membrane 
hangs  down  into  the  ventricle,  it  grows  thinner  and  is  divided 
into  fringes.  How  these  fringes  can  do  the  office  of  valves  is 
next  to  be  explained.  The  tags  and  fringes  of  this  membrane 
ai’e  actually  tied  to  the  inside  of  the  ventricle  by  many  strings, 
which  being,  like  the  valves,  of  a tendinous  nature,  are  called 
CORD®  TENDiNE/E,  Or  tendinous  cords ; and  these  cords  being 
attached  to  little  processes  projecting  from  the  muscular  sub- 
stance of  the  hpart,  these  processes  are  named  coLUMNiE 
carnea:,  or  fleshy  columns.  Of  these  tyings  of  the  valves 
there  are  three  chief  points  ; the  whole  circle  seems  to  be  di- 
vided into  three  sharp-pointed  valves ; they  are  named  vae- 
vuLiE  TRicuspiDES,  01’  tliree-pointed,  or  they  are  still  some- 
times called  Triglochine  Valves.  The  valves  fall  down  easily 
when  the  blood  goes  down  through  them,  and  they  rise  readily 
and  quickly  whenever  the  blood  gets  behind  them  : when  the 
ventricle  is  full  the  valves  are  still  open,  but  when  the  ventricle 
contracts,  the  blood  throws  up  the  valves,  and  closes  the  open- 
ing into  the  auricle,  and  now  the  tendinous  cords  and  fleshy 
columns  support  the  margins  of  the  valves,  so  that  they  give 
them  strength  to  support  the  heart’s  action. 

6.  The  VENTRICLE  of  the  right  side  (Z/)  is  like  its  auricle, 
larger  than  the  same  parts  on  the  left  side;  for  this  auricle 


OF  THE  HEART. 


325 


and  ventricle  of  the  right  side  have  the  weight  of  the  whole 
blood  of  the  body  pressing  upon  them.  They  are  subject  to 
occasional  fulness,  for  they  must  be  dilated  by  many  acci- 
dents, as  labour,  violent  struggles,  &zc.  which  send  the  blood 
too  quickl)^  upon  the  heart ; while  the  left  auricle  and  ven- 
tricle, on  the  other  hand,  can  never  be  over  loaded,  as  long 
as  the  pulmonic  artery  preseiwes  its  natural  size,  for  that  artery 
continues  always  the  measure  of  the  quantity  of  blood  which 
they  receive.  The  ventricle  is  thick,  strong,  fleshy.  Its  in- 
ner surface  is  extremely  irregular  ; it  puts  out  from  every 
part  of  its  surface  very  strong  fleshy  columns.  These  fleshy 
columns  are  irregular  in  size,  big,  strong,  running  along  the 
length  of  the  ventricle ; some  across  the  ventricle,  so  as  to 
connect  its  opposite  walls  together ; some  have  the  tendons 
of  the  valves  fixed  to  them  ; all  of  them  have  perfect  con- 
tractile power,  and  are  indeed  tire  strongest  muscles  of  the 
heart.  Betwixt  the  fleshy  columns,  there  are,  of  course,  very 
deep  and  irregular  grooves ; and  among  the  confused  roots 
of  these  fleshy  columns  the  blood  often  coagulates  after  death, 
seldom  before  it,  into  the  form  of  what  are  called  polypi  of 
the  heart.  Yet  still  the  walls  of  the  right  ventricle  (//) — are 
thinner,  the  fleshy  columns  smaller,  the  cavity  greater,  than 
those  of  the  lelt  side ; the  right  ventricle  of  the  heart  has  also 
a peculiar  form  for  the  septum  cordis,  a partition  betwixt 
the  righi  anti  left  heart,  is  not,  as  generally  supposed,  a part 
coniu  :a  to  both;  but  the  left  ventricle  is  much  longer  and 
more  than  the  right  one  ; the  septum  belongs  almost 

entnv^  r to  Lhe  left  ventricle  ; the  right  ventricle  which  is  much 
bigger,  laxer,  flatter,  and  thinner  in  the  tvalls,  is,  as  it  were, 
wrapped  round  the  left ; and  thus  the  left  ventricle  alone 
forms  he  acute  apex  of  the  heart,  and  the  left  ventricle  of 
necessity  bulges  very  much  into  the  cavity  of  the  right,  since 
the  right  ventricle  is  so  much  larger,  and  in  a manner  wrapped 
round  it.  In  both  ventricles,  it  is  very  remarkable,  that  to- 
wards the  opening  of  the  auricle  the  surface  of  the  ventricle 
is  very  rugged,  ii-regular,  and  crossed  with  columns;  carnete, 
while  a smooth  and  even  lubricated  channel  marked  (m)  leads 
towards  the  artery. 

7.  The  PULMONIC  artery  arises  from  the  right  ventricle, 
to  carry  out  the  blood  close  by  the  great  opening  at  which 
the  auricle  pours  it  in ; the  aiTery  rises  at  its  root  in  a very 
bulging  triangular  shape.  It  is  the  valve  within  the  mouth  of 
the  artery  that  gives  it  this  very  peculiar  shape  without ; for 
the  bulging  root  is  divided  into  three  knobs,  indicating  the 
places  of  the  three  valves,  the  artery  dilating  behind  each  valve 
into  a little  bag,  which,  when  it  is  described,  is  called  its  sinus. 


326 


OF  THE  MECHANISM 


8.  -This  VALVE  of  the  pulmonic  artery  (n) — has  a more 
perfect  and  simple  form  than  that  of  the  auricle.  The  valves 
in  the  mouth  of  each  of  the  great  arteries  are  three  in  num- 
ber ; they  are  thin  but  strong  membranes,  rising  from  the  circle 
of  the  artery,  where  it  comes  off  from  the  heart : each  valve 
is  semilunar : its  larger  and  looser  edge  hangs  free  into  the 
cavity  of  the  artery  ; the  edge  is  a little  thicker  than  the  rest 
of  the  valve  ; the  three  valves  together  form  one  perfect  cir- 
cle, which  closes  the  mouth  of  the  artery  so  that  no  grosser 
fluid,  nor  hardly  air,  can  pass.  When  they  are  filled  till  they 
become  very  tense,  each  valve  forms  a kind  of  bag ; so  that 
when  you  look  at  the  mouth  of  a dried  artery,  they  appear 
like  neat  round  bags  ; and  when  they  are  likely  to  be  forced, 
the  little  horns  or  tags  by  which  each  valve  is  fixed  into  the 
coats  of  its  artery,  become  so  tense  as  to  do  the  office  of  a 
ligament : these  are  called  the  semilunar  or  sigmoid 

VALVES. 

Now  the  eondition  of  the  ventricle  while  it  is  contracting 
is  well  understood : the  auricle  by  its  action  lays  down  the 
tricuspid  or  auricular  valve,  and  fills  the  ventricle  ; the  ven- 
tricle cannot  feel  the  stimulus  of  fulness  till  its  valves  rise,  and 
its  cordae  tendineae  begin  to  pull ; and  the  ventricle  could  not 
be  close  for  acting,  nor  its  walls  perfect,  it  could  not  in  short 
be  an  entire  cavity,  till  the  tricuspid  or  auricular  valves  were 
completely  raised.  But  there  is  another  opening  of  the  ven- 
tricle, viz.  that  into  the  artery,  which  must  be  also  shut ; this 
is  one  of  the  several  instances  of  the  subordination  of  these 
actions  one  to  another ; for,  first,  the  auricle  acts,  then  the 
ventricle,  then  the  artery;  so  that  the  auricle  and  the  artery 
are  acting  in  the  same  moment  of  time  ; the  artery  by  acting 
throws  down  its  valve,  and  closes  that  opening  of  the  ventricle, 
while  the  auricle  is  filling  it  with  blood  ; and  again,  the 
moment  that  the  ventricle  is  filled,  both  the  auricle  and 
artery  are  in  a state  of  relaxation,  the  auricular  valve  rises  so 
as  to  close  the  ventricle  on  that  side ; and  the  arterial  valve 
falls  down,  both  because  the  artery  has  ceased  acting,  and 
because  the  valve  is  laid  flat  by  the  whole  blood  of  the  ven- 
tricle rushing  through  it.  Hence  it  is  very  obvious,  that  the 
right  ventricle  could  neither  be  filled  nor  stimulated,  unless  the 
opening  toward  the  artery  were  close  during  the  time  of  its 
filling ; and  again,  it  is  obvious  that  this  valve  cannot  be  laid 
down  by  any  other  power  than  that  of  the  artery  itself ; who 
then  can  doubt  that  the  artery  has  in  itself  (like  the  ventricle) 
a strong  contractile  power  ? That  it  is  the  stroke  of  the 
artery  succeeding  that  of  the  heart  that  lays  down  this  valve 
so  closely,  is  proved  by  this,  that  in  many  animals,  in  fishes, 


/'ol.JL 


Jlr/ur,n,/n„,  rh.  t.urk  /um  ,r  t!u  H,  ,nt  _rhr  ,,rn,t  fr,r„„rv  \ _n,c 
■ v,„/,r  nfrhrAvrirlr_uml  H,r  rnt,;nu;-  of  thr  JM„„.w,rv  Vn„.i 


/'.  /S. 


N."y 


brJ/.  , 


Lriny 


OF  THE  HEART. 


327 


for  example,  the  aorta  is  as  plainly  muscular  as  the  heart  it- 
self, it  is  like  a second  heart ; and  in  fishes  the  vessel  returning 
from  the  gills,  and  often  in  human  monsters,  the  artery  alone, 
by  its  own  muscular  power,  moves  the  whole  circulation  with- 
out any  communication  with  the  heart.  In  fishes  there  is  no 
second  heart  for  the  circulation  of  the  body ; and  in  monsters 
the  heart  is  sometimes  wanting,  and  there  is  found  nothing  but 
a strong  aorta  to  supply  its  place.  This  stroke  of  the  pulmo- 
nic artery,  then  (which  the  heart  excites,)  pushes  the  blood 
through  the  lesser  circle  or  circulation  of  the  lungs,  and  by 
the  pulmonic  veins  it  is  poured  into  the  left  side  of  the  heart. 

9.  The  LEFT  AURICLE  of  the  heart  is  unlike  the  right  auricle 
in  these  respects  : the  sinus,  or  that  part  which  consists  of  the 
dilatation  of  the  pulmonic  veins,  is  smaller,  while  the  auri- 
cula, which  is  the  more  muscular  part,  is  larger,  the  pulmonic 
veins  come  in  four  great  trunks  from  the  lungs,  two  from  the 
right  side  and  two  from  the  left ; two  great  veins  then  enter  at 
each  side  of  the  left  auricle,  by  which  it  gets  a more  square 
form.;  the  whole  of  the  left  sinus,  which  forms  the  chief 
bulk  of  this  part,  is  turned  directly  backwards  towards  the 
spine,  and  is  not  to  be  seen  in  any  common  \new  of  the  heart ; 
but  I have  here  added  a plan  of  the  back  part  of  the  heart,* 
shewing,  1.  How  the  left  ventricle  lies  behind  ; 2.  How  the 
left  auricle  is  turned  still  more  directly  backwards ; 3.  How 
the  pulmonic  veins  enter  into  it  in  four  great  branches,  so  as  to 
give  a square  or  box-like  form,  compared  with  the  gliding, 
gentle  shape  of  the  right  auricle ; 4.  How  the  pulmonie 
artery  comes  out  from  under  the  arch  of  the  aorta,  dividing 
into  its  two  great  branches  for  each  side  of  the  lungs  ; and,  5. 
How  the  aorta  arches  over  it,  towers  above  all  the  other  ves- 
sels, and  is  known  always  among  the  vessels  of  the  heart  by 
the  carotid  and  subclavian  arteries  which  come  off  from  its 
arch.  On  the  plan.  No.  6.  are  seen — (00)  the  two  pulmonic  veins 
entering  from  each  side  of  the  lungs — {j}p)  the  opening  of 
these  into  the  auricle — [qq)  the  sinus  formed  in  part  by  the 
dilatation  of  these  veins,  and, — (r)  the  auricula  or  little  ear, 
from  which  the  whole  bag  is  named  auricle. 

10.  The  valves  which  guard  the  left  auricle  are  seen  heref 
(ss) ; — Now  it  is  to  be  remembered  that  the  left  auricle  is 

* Explanation  of  the  back  view  of  the  he-abt,  No.  9. 

1.  The  loft  V'^entricle — -2,  The  left  Auricle — 3S3  3,  The  four  Pulmonic  Veins — 4 4. 
The  two  great  branches  of  the  Pulmonic  Artery — 5,  Tlie  Aorta — 6,  Tlia  Carotids  and 
Subclavians— 7,  The  Cava  Descenderis — 8,  The  Cava  Ascendens,  with  all  its  branches 
from  the  Liver — 9,  The  great  Coronary  Vein  running  along  the  back  of  the  Heart  betwixt 
the  Auricle  and  Ventricle  in  a groove  surrounded  by  fat. 

t This  begins  the  description  of  the  left  side  of  the  heart,  and  the  description  follow* 
the  plan,  No.  6. 


328 


OF  THE  MECHANISM 


smaller  than  the  right,  that  the  circle  or  opening  of  the  left 
auricle  is  of  course  smaller  than  that  of  the  right ; that  while 
it  requires  a valve  divided  into  three  points  to  fill  the  opening 
of  the  right  auricle,  a valve  divided  only  into  two  points 
suffices  for  the  opening  of  the  left  auricle  ; this  is  the  reason 
of  this  slight  variety  of  shape  betwixt  the  two  auricular  valves,  i 
and  is  also  the  reason  of  the  valve  of  the  right  side  being 
called  TRICUSPID  or  three-pointed,  while  this  of  the  left  side, 
from  some  very  slight  resemblance  to  a mitre,  is  named 
VALVULA  MiTKALis,  tile  MITRAL  VALVE.  Ill  all  Other  points 
this  valve  is  the  same  with  that  of  the  right  side,  it  has  the  ; 
same  apparent  thinness,  for  it  is  even  transparent,  the  same 
real  strength,  the  same  column^e  carneie  and  tendinous 
strings  to  support  it ; the  same  rough  irregular  surface  towards 
the  opening  of  the  auricle  ; the  same  smooth  gutter  leading  j 

towards  the  artery.  The  constitution  of  all  these  parts,  in  | 

short,  is  expressly  the  same  ; so  that  even  concerning  the  left 
ventricle  there  is  nothing  further  to  be  observed,  but  that 
while  it  is  much  longer  than  the  right  ventricle,  it  is  much 
smaller  in  its  whole  cavity,  is  much  stronger  in  its  columnar 
carnea:,  and  much  thicker  in  its  fleshy  walls,  as  at  (it)  where 
it  is  seen  to  be  thicker  than  the  right  ventricle,  it  is  indeed 
nearly  three  times  as  thick. 

11.  The  SEMILUNAR  VALVES  of  the  aorta  are  also  seen  in 
this  general  plan  at  (w) — where  manifestly  the  general  struc- 
ture, and  general  intention  of  the  valves  are  the  same  as  in  i 
those  of  the  pulmonic  artery;  but  still  we  find  at  every  point 
marks  of  superior  strength  and  more  violent  action  in  the  left 
side  of  the  heart ; for  though  this  valve  be  expressly  like  that 
of  the  pulmonic  artery,  and  named  like  it  semilunar,  yet  it 

is  thicker  and  stronger  in  its  substance,  and  is  peculiarly 
guarded  by  three  small  hard  tubercles,  which  being  placed  ^ 
one  in  the  apex  or  point  of  each  valve,  meet  together  when 
the  valve  is  close,  and  give  a more  perfect  resistance  to  the 
blood,  and  prevent  the  valve  being  forced  open.  These  are  to 
be  seen  chiefly  in  the  opposite  drawing,  and  from  their  being 
of  the  size  of  sesamum  seed,  they  have  the  name  of  Corpora 
Sesamoidea  ; sometimes  they  are  named  Corpuscula  Arantii. 

12.  The  AORTA  arises  from  its  ventricle  very  large  and 
strong  ; it  swells  still  more  at  its  root  than  the  pulmonic  artery 
does ; the  three  subdivisions  of  this  sw'elling,  which  mark  the 
places  of  the  semilunar  valves,  are  very  remarkable  ; the  cur- 
vature at  the  arch  of  the  aorta  is  called  its  great  sinus,  and 
these  three  smaller  bags  are  called  the  three  lesser  sinuses  ol 
the  aorta. 


OF  THE  HEART. 


329 


Fig.  10.  shows  the 
aorta  entire,  but  its  root 
within  the  heart  opened 
so  as  to  show  its  valve-(a) 
The  body  of  the  aorta  ; 
the  arch  is  marked  by  bh, 
the  carotids  and  subcla- 
vians — (c)  Shows  one  of 
the  coronary  arteries  or 
artery  of  the  heart. — (d) 
A part  of  the  walls  of  the 
heart. — (e  e e)  The  three 
valves  stuffed  and  turgid 

towards  the  heart. 

N“  11.  shows  the  lower 
part  of  the  aorta  cut  open, 
and  two  of  the  valves — ^ 
(a«) — entire  ; and  the 
the  third  valve — {bh) — 
cut  in  two  by  slitting  up 
the  artery. — And  (rr) 
shows  the  mouths  of  the 
two  coronary  arteries. — 
N°  12.  shows  the  aorta 
slit  only  in  its  lower  part, 
and  the  valves  {aa)  and 
the  mouths  of  the  coro- 
nary arteries  { h)  are 
seen  in  their  natural  si- 
tuation.— N.  B.  In  these 
two  last  drawings  the 
corpora  sesamoidca  are 
distinctly  seen  in  the 
central  part  of  the  edge 
of  each  valve,  and  they 
need  no  letter  to  dis- 
tinguish them. 


530 


«F  THE  JlECHANlSjr 


OF  THE  CORONARY  VESSELS. 

But  there  still  remains  to  be  explained  that  peculiar  circi!' 
lation  by  which  the  heart  itself  is  nourished,  and  yet  there  is 
nothing  in  it  very  different  from  the  usual  form  of  arteries  and 
Veins  ; it  is  a part  of  the  general  circulation  of  the  body,  for 
the  heart  is  nourished  by  the  two  first  branches  which  the 
aorta  gives  off.  The  circulation  destined  for  the  nourishment 
of  the  heart  is  peculiar  in  this  chiefly,  that  the  forms  of  the 
arteries  and  veins  of  the  heart  are  beautiful,  and  that  the  ar- 
teries rise  just  under  the  valves  of  the  aorta,  while  the  veins 
end  with  one  great  mouth  in  tlie  right  auricle.  The  coronary 
arteries  are  two  in  number,  of  the  size  of  crow-quills ; we  see 
from  the  inside  of  the  artery  their  mouths  opening  above  the 
sigmoid  valves.  One  artery  comes  from  the  lower  side  of  the 
aorta  ; it  lies  towards  the  right ; it  belongs  chiefly  to  the  right 
ventricle  ; it  comes  out  first  betwixt  the  roots  of  the  aorta  and 
pulmonic  arteries ; it  passes  in  the  furrow  betwixt  the  right 
ventricle  and  auricle,  and  turning  round  arrives  at  the  back 
part  of  the  heart,  and  runs  down  along  the  middle  of  that  flat 
surface  which  lies  upon  the  diaphragm  ; and  when  it  arrives  at 
the  apex  of  the  heart,  its  extreme  arteries  turn  round  the 
point  and  inosculate  with  the  opposite  coronary.  The  other 
coronary  belongs  in  like  manner  to  the  left  side  of  the  heart, 
and  arises  from  the  upper  side  of  the  aorta ; it  first  goes  out 
betwixt  the  pulmonic  artery  and  the  left  auricle,  and  then 
turning  downwards  upon  the  heart,  it  runs  along  that  groove 
which  is  betwixt  the  ventricles,  and  marks  the  place  of  the 
partition  or  septum  ventriculorum ; its  chief  branches  turn 
towards  the  left  ventricle,  and  branch  out  upon  it;  it  belongs 
as  peculiarly  to  the  left  side  of  the  heart  as  the  other  does  to 
the  right  side  : after  supplying  the  left  ventricle,  &ic.  it  turns 
over  the  point  of  the  heart  to  meet  the  extremity  of  the  first, 
and  inosculate  will)  it.  Both  these  arteries  give  branches  not 
only  to  the  flesh  of  the  ventricles,  but  to  the  auricles,  and  also 
to  the  roots  of  the  great  arteries,  constituting  the  vasa  vaso- 
RUM,  as  such  minute  branches  sent  to  vessels  are  called. 

The  GREAT  coronary  vein  which  collects  the  blood  of 
these  arteries,  arises  in  small  branches  all  over  the  heart ; 
these  meet  so  as  to  form  a trunk  upon  the  forepart  of  the 
heart  where  the  septum  or  union  of  the  ventricles  is.  While 
small,  the  veins  accompany  their  respective  arteries  ; but  after 
the  great  trunk  is  formed,  the  vein  takes  its  own  peculiar 
route.  When  the  trunk  of  the  great  coronary  vein  (accom- 
panied by  several  lesser  veins)  arrives  at  the  auricle,  it  runs  in 


OP  THE  HEART. 


331 


feetwcen  the  left  auricle  and  left  ventricle  ; it  turns  all  round 
the  back  of  the  auricle  till  it  gets  to  the  right  side  of  the 
heart ; it  lies  in  the  deep  groove  betwixt  the  auricle  and  ven- 
tricle, surrounded  with  much  fat ; and  having  almost  entirely 
encircled  the  heart,  it  discharges  its  blood  into  the  I'ight 
auricle,  close  by  the  entrance  of  the  lower  cava.  The  open- 
ing is  very  large  ; it  lies  just  above  the  tendinous  circle  of  the 
auricle,  and  it  is  guarded  with  a strong  semilunar  valve.  This 
is  the  great  coronary  vein  ; all  the  veins  which  appear  upon 
the  heart  are  but  branches  of  it ; what  are  called  the  middle 
vein  of  the  heart,  the  vein  of  the  right  auricle,  the  vena  in- 
nominata,  &ic.  are  all  but  branches  of  the  great  coronary  vein 
running  along  the  right  side  or  lower  surface  of  the  heart  ; if 
there  were  to  be  any  marked  distinction,  it  should  be  into  the 
GREAT  CORONARY  VEIN  belonging  to  the  left  side  of  the  heart, 
and  the  vena  innominata  belonging  to  the  right  side.  But 
one  thing  more  is  to  be  observed  ; viz.  that  upon  the  inner 
surface  of  the  right  auricle  may  be  seen  many  small  oblique 
and  very  curious  openings,  which  serve  for  the  mouths  of 
veins,  while  their  obliquity  performs  the  office  of  a valve. 
This  name  of  coronary  vessels  is  a very  favourite  one  with 
anatomists,  and  is  applied  wherever  vessels  surround  the  parts 
which  they  belong  to,  however  little  this  encircling  may  be 
like  a crown  ; and  it  is  thus  that  we  have  the  coronary  arteries 
of  the  stomach,  coronary  arteries  of  the  lips,  and  coronary 
arteries  of  the  heart.  But  these  vessels  of  the  heart  are  really 
very  beautiful,  and  have  some  things  very  peculiar  in  their  cir- 
culation : first,  with  regard  to  the  coronary  arteries,  they  lie 
with  their  mouths  under  the  sigmoid  valves  ; or  at  least  in  so 
equivocal  a manner,  that  their  peculiar  posture  has  given  rise 
to  violent  disputes ; viz.  whether  they  be  filled,  like  all  the 
other  arteries,  by  the  stroke  of  the  heart,  or  whether  they  be 
covered  by  the  valve  so  as  to  let  the  blood  rush  past  them  during 
the  action  of  the  heart. 

We  see  the  opening  of  the  coronary  arteries  rather,  as  I 
imagine,  under  the  valve;  though  Haller  says  they  are  above 
the  valve,  and  that  the  highest  point  to  which  the  margin  of 
the  valve  reaches  in  very  old  men  is  below  the  opening  of  the 
coronary  artery,  and  half  way  betwixt  it  and  the  bottom  of  the 
sinus  or  little  bag  behind  the  valve.  But  let  this  be  as  it  will, 
if  the  condition  of  the  aoi'ta  be  considered,  it  will  be  found  to 
make  no  difference  ; for  though  the  valves  rise  and  fall,  are  at 
one  time  fully  opened,  and  at  another  time  closely  shut,  still 
in  both  these  conditions  of  the  valve  the  aorta  is  as  full  as  it 
can  hold ; its  contraction  instantaneously  follows  that  of  the 
heart,  but  its  contraction  is  not,  like  that  of  the  heart,  surh 


332 


OF  THE  MECHANISM 


as  to  bring  its  sides  together ; on  the  contrary,  the  aorta  is 
full  when  tlie  heart  strikes,  the  action  of  the  heart  distends  it 
to  the  greatest  degree,  the  aorta  re-acts  so  as  to  free  itself  of 
this  distention,  but  still  it  remains  in  some  degree  full  of  blood  ; 
else  how  could  this,  like  every  other  artery,  preserve  always 
its  form  and  apparent  size?  In  this  condition  of  matters,  it  is 
obvious  that  the  coronary  branches  are  on  the  same  footing 
with  all  the  other  branches  of  the  aortic  system  ; that,  like  all 
the  other  arteries,  they  first  feel  the  stimulus  of  fulness  from 
the  push  of  the  heart,  and  along  with  it  the  stroke  of  the 
aorta. 

Secondly,  with  regard  to  the  coronary  veins  a dispute  has 
arisen  more  violent  than  this ; for  it  has  been  doubted  whe- 
ther the  coronary  veins,  large  as  they  are,  do  actually  convey 
the  whole  of  the  blood  which  the  coronary  artery  gives  out. 
Veussens  believed  that  some  of  the  coronary  arteries  opened 
directly  into  the  cavities  of  the  heart,  without  the  interposi- 
tion of  veins,  Thebesius,  after  him,  believed  that  there 
were  some  shorter  ways  by  which  the  blood  was  returned  ; not 
by  a long  circle  into  the  right  auricle,  but  directly  into  the 
ventricles  of  the  heart.  Veussens,  Thebesius,  and  others  who 
belong  to  their  party,  pretended  to  prove  this  fact  by  injec- 
tions : but  what  doctrine  is  there  which  such  clumsy  anatomy 
and  awkward  injections  may  not  be  made  to  prove  ? They 
used  mercury,  tepid  water,  and  air;  and  they  forced  these, 
the  most  penetrating  of  all  injections,  till  they  exuded  upon 
the  inner  surface  of  the  heart ; but  if  they  had  fixed  their 
tubes,  not  into  the  coronary  artery,  but  into  the  aorta,  and 
had  proceeded  to  inspect,  not  the  heart,  but  all  the  viscera  of 
the  body,  they  would  have  found  their  injections  exuding  from 
every  surface;  of  the  pleura  and  lungs;  of  the  peritoneum, 
and  intestines ; of  the  brain  and  dura  mater ; of  the  mouth 
and  tongue;  and  universally  through  the  cellular  membrane 
of  the  whole  body  ; but  if  any  coarse  injection,  as  tallow  or 
wax,  be  used,  following  this  natural  course,  it  keeps  within  the 
arteries  and  veins,  and  if  thin  and  well  prepared,  finds  its 
way  back  to  the  auricle  of  the  heart  ; but  this  injection 
also  is  extravasated  and  is  found  in  the  cavities  of  the 
heart. 

Du  Verney  was  so  far  engaged  in  this  question,  that  having 
an  opportunity  of  dissecting  the  heart  of  an  elephant,  he  tied 
up  the  coronary  arteries  and  veins,  washed  and  cleaned  very 
thoroughly  the  cavities  of  the  heart;  and  then  tried,  by 
squeezing,  and  all  kinds  of  methods,  to  make  that  blood 
wdiich  \ras  tied  up  in  the  coronary  arteries  and  veins  exude 
upon  the  inner  surface  of  the  heart,  but  with  no  effect. 


^7'07?l  f/u'I£f(f7'f-  of  ((  (7u7d 
(xhout  S 07'^  j/oo7\?  old . 


of  t/ie  diatffs , b.b,  f7ie  jPer'icaj^iium  hj/  io7nc7t  t7ieJfoa7t  /j  sns- 
■/fonded , c.c,t7ieJ7mfr7c7t’s  of  t7tt\Hfa7^,  d.d.  t7ze^oTta  eziczrcled  t7e 
d^er7oei7'dium , e.e.e.e.  t7ie  frzZ^edznoazz  a7id  Cczroizd uir-tenes,  g.  t7ie jzrzidoff' 
ptrrt  of  t7iediT7/7ft^7t7^c7c,  ~\\.f7zr  (^rroa  de^rozzdozis-  7h/  7o7uc7i  t7ieJfeoTt 
j?ort  S7{^j?e7ide7f , \.x.t7ie  Cava  Offrezidezz^c  ioit7i  ajoenczl jzazfsed  uj?  into  dz.r 
dii^^/zt.AiznWo , t7u‘sj7 077077  is-  boTiind  777e^7istac7iia77J7i77'o,/'7te-Enstar7aa7f 
TTili^o  itself  IS  7nnr7ied  k,  tTie  h'ttloT'alve  oft7ze  CoTonary  Tiiii  ivbizo/i  is  oon- 
Tieotf’ii  ivitT?  if  is  marA'od  m . 


OF  THE  HEART. 


333 


On  the  present  occasion,  a theoretical  answer  happens  to 
be  as  satisfactory  as  the  most  correct  experiments  : and  it  is 
this,  If  there  really  were  to  be  formed  (by  disease,  for  ex- 
ample,) those  numerous  openings  which  Thebesius  and  Veus- 
sens  describe,  then  the  blood  flowing  all  by  these  shorter  and 
easier  passages,  none  could  come  to  the  great  coronary  vein  ; 
its  ofiice  would  be  annihilated  ; and  itself,  contracting  gradu- 
ally, would  soon  cease  to  exist. 


OF  THE  EUSTACHIAN  VALVE. 

There  remains  to  be  explained  in  the  mechanism  of  the 
heart  one  point ; and  which  I have  separated  from  the  others  j 
not  because  it  is  the  least  Important,  but  because  it  is  the 
most  difiicult,  and,  if  I may  be  allowed  to  say  so,  not  yet 
thoroughly  understood ; I mean  the  anatomy  of  the  Eusta- 
chian valve;  which,  if  it  bad  been  easily  described,  should 
have  been  first  described  ; for  it  is  a valve  which  lies  in  the 
mouth  of  the  lower  cava,  just  where  that  vein  enters  the  right 
auricle  of  the  heart.  How  imperfect  a valve  this  is,  how 
difficult  to  dissect  or  to  explain,  may  CEisily  be  known  from 
this,  that  Winslow  was  first  incited  to  look  for  the  valve  by 
some  hints  in  Sylvius  : he  was  soon  after  fairly  directed  to  it 
by  finding  it  in  the  tables  of  the  Eustachius,  which  were  then 
first  found  and  published  by  Lancisi,  after  the  author  had 
been  dead  150  years  ; and  yet  with  all  this  assistance  Winslow 
sought  for  it  continually  in  vain,  till  at  last  he  reflected,  that 
by  cutting  the  heart  in  its  forepart,  he  must  have  always  in 
his  dissections  destroyed  any  such  valve ; by  opening  the 
back  part  of  the  cava  he  at  last  saw  the  valve,  and  demonstra- 
ted it  to  the  Academy  of  Sciences  in  France  ; and  having  just 
received  from  Lancisi  his  edition  of  the  Eustachian  Table, 
so  long  hidden,  and  since  so  outrageously  praised,  he  called 
it  VALVULA  Eustachiana,  a name  which  it  has  retained  to  this 
day,  and  he  added  keticulakis,  to  express  its  lace-like  netted 
appearance  at  its  upper  edge.  From  Winslow’s  time  to  this 
present  day,  that  is,  for  eighty  years,  there  has  been  no  good 
drawing,  nor  even  any  perfect  description  of  the  valve  ; and 
in  the  confusion  of  opinions  upon  the  subject,  what  its  use 
may  be  no  one  knows. 

The  Eustachian  valve  lies  in  the  mouth  of  the  ascending 
cava,  just  where  that  great  vein  is  joined  to  the  auricle  of  the 
heart.  It  looks  as  if  formed  merely  by  the  vein  entering  at 
an  acute  angle,  and  by  the  inner  edge  of  the  vein,  or  that 
which  is  joined  to  the  auricle,  rising  high,  so  as  to  do  the 


334 


OF  THE  MECHANISM 


office  of  a valve.  The  very  first  appearance  of  the  valve,  ant! 
its  place  just  over  the  mouth  of  the  cava,  seems  to  point  out 
that  use  which  Lancisi  has  assigned  it,  viz.  to  support  the 
blood  of  the  upper  cava,  and  prevent  that  column  of  blood 
which  descends  from  the  cava  gravitating  upon  the  opposite 
column  which  comes  from  the  liver  and  lower  parts  of  the 
body  ; and  yet  this,  most  likely,  is  not  its  use.  The  valve 
somewhat  resembles  a crescent,  or  the  membrane  called  hy- 
men. It  occupies  just  that  half  of  the  cava  which  is  nearest 
the  auricle.  Its  deepest  part  hangs  over  the  mouth  of  the 
cava,  and  is  nearly  half  an  inch  in  breadth,  seldom  more, 
often  less,  sometimes  a mere  line.  Its  two  horns  extend  up 
along  the  sides  of  the  auricle  ; the  posterior  horn  arises  from 
the  left  of  the  isthmus,  as  it  is  called,  or  edge  of  the  oval  hole ; 
its  anterior  horn  arises  from  the  vena  cava,  where  it  joins  the 
auricle.  Behind  the  valve  the  remains  of  the  foramen  ovale 
may  be  seen,  now  shut  by  its  thin  membrane,  but  still  very 
easily  distinguished  ; for  its  arch-like  edges  are  so  thick, 
strong,  and  muscular,  that  they  look  like  two  pillars,  and 
thence  are  called  the  columns;  fokaminis  ovalis  : these  two 
pillars  were  called  isthmus  Vieussenii,  and  by  Haller  are 
named  annulis  fossae  ovalis,  while  the  remains  of  the  hole 
itself  is  so  deep  that  it  is  named  the  fossa  ovalis.  Before 
the  Eustachian  valve  lies  the  great  opening  into  the  ventricle  ; 
but  betwdxt  that  and  the  valve  there  is  a fossa  or  hollow,  in 
which  lies  the  opening  of  the  great  coronary  vein  ; and  the 
valve  which  covers  the  coronary  vein  is  a neat  small  slip  of 
w'hite  and  very  delicate  membrane,  the  one  end  of  which  con- 
nects itself  with  the  forepart  of  the  Eustachian  valve  ; so  that 
both  valves  are  moved  and  made  tense  at  once. 

The  Eustachian  valve  is  in  general  thick  and  fleshy ; it  is 
sometimes  reticulated  or  net-like  even  in  the  foetus,  but  by  no 
means  so  often  as  to  vindicate  Winslow,  in  adding  reticulare 
to  the  name;  it  grows  reticulated  chiefly  in  the  adult.  The 
only  beautiful  drawing  that  we  have  of  a reticular  Eustachian 
valve  is  in  Cowper  • and  that  was  from  a man  of  eighty  years 
of  age.  Perhaps  in  eight  or  ten  hearts  you  will  not  find  one 
that  is  reticulated  in  the  least  degree  ; in  old  men  it  is  reticu- 
lated, just  as  all  other  valves  of  the  heart  are,  not  by  any  thing 
peculiar  to  the  constitution  of  this  valve;  not  by  the  pressure 
of  the  blood  and  continual  force  of  the  vessels,  as  Haller  re- 
presents ; but  by  the  gradual  absorption  which  goes  on  in  old 
age,  and  which  spares  not  the  very  bones,  for  even  they  grow 
thin  and  in  many  places  transparent. 

This  is  the  simple  description  of  a valve,  which  has  been 
the  occasion  of  more  controversy  than  the  circulation  of  the 


©F  THE  HEART. 


335 


foetus  and  the  use  of  the  oval  hole  Winslow  first  began  about 
eighty  years  ago  to  observe  the  connections  and  uses  of  this 
valve ; he  laid  it  down  as  an  absolute  fact  that  this  valve  was 
almost  peculiar  to  the  foetus ; that  it  was  perfect  only  while 
the  foramen  ovale  was  open  ; that  it  vanished  gradually  as  the 
foramen  ovale  closed ; that  in  the  adult  it  was  seldom  seen 
unless  the  foramen  ovale  was  also  open  by  chance.  It  is  in- 
credible what  numbers  of  anatomists  followed  this  opinion  ; for 
the  difficulty  of  dissecting  the  valve  made  it  always  easier  to 
say  that  it  was  only  in  the  foetus  that  it  could  be  found  : it  is 
also  incredible  what  absurd  consequences  arose  from  this  doc- 
trine, which,  after  all,  is  but  a dream,  for  in  fact  the  valve  is 
more  easily  shown  in  the  adult  heart.^' 

The  foundation  being  now  laid  for  connecting  this  valve  with 
the  peculiar  circulation  of  the  foetus,  they  conceived  the  folloAV- 
ing  theory,  which  has  come  down  to  this  very  day  ; viz.  that 
in  the  child,  the  great  object  of  nature  in  arranging  its  vessels, 
was  to  convey  the  blood  which  came  fresh  from  the  mothers 
system  directly  into  the  carotids,  and  so  plump  into  the  head 
at  once.  The  pure  blood  from  the  mother  comes  through 
the  liver  by  the  ductus  venosus ; it  is  deposited  in  the  lower 
cava  at  the  right  side  of  the  heart;  and  these  anatomists  sup- 
posed that  this  current  oi  fresh  blood  was  directed  by  the  Eu- 
stachian valve  into  the  oval  hole,  through  that  into  the  left  auri- 
cle and  ventricle,  and  from  these  directly  into  the  aorta  and 
carotids ; w’bile  the  foul  blood  of  the  upper  cava  went  down 
into  the  right  auricle  and  ventricle,  and  from  that  into  the 
ductus  arteriosus,  and  so  away  down  to  the  lower  and  less  noble 
parts  of  the  body,  and  to  the  umbilical  arteries,  and  so  out  of 
the  system ; for  the  ductus  arteriosus,  which  comes  from  the 
right  ventricle  in  the  foetus,  joins  the  aorta  only  as  it  goes  down 
the  back,  and  none  of  its  blood  can  pass  upwards  into  the  head. 

This  is  the  puerile  theory,  which,  modified  in  various  ways, 
has  amused  the  French  Academy,  or  rather  been  the  cause  of 
a perpetual  civil  war  in  it,  for  a hundred  years.  This  doctrine 
began  with  Winslow,  it  is  still  acknowledged  by  Sabatier; 
and  Haller,  after  announcing  a theory  not  at  all  differing  from 
this,  challenges  it  as  his  own  theory ; “ hanc  meam  conjectii- 

* One  author,  I 6nd  in  the  Acta  Vindobonensia,  is  exceedingly  angry  indeed  with  all  tiie 
great  anatomists,  for  not  connecting  more  strictly  with  eacli  other,  the  anatomy  and  accidents 
of  the  foramen  ovale,  and  Eustachian  valve  ; with  Morgani,  Albinus,  and  V/iedbriecht,  he 
IS  oftended  for  saying  that  tliey  had  seen  the  foramen  ovale  open,  without  saying  one  word 
concerning  the  state  of  this  valve ; and  witli  Lieutaud,  Portal  and  others  again,  he  is  equally 
offended  that  they  should  have  had  opportunities  of  seeing  the  Eustachian  valve  entire  with- 
out inquiring  into  the  condition  of  the  oval  hole.  The  reason  of  all  this  is  very  plain ; the 
oval  hole  had  not  been  oiien,  neither  in  the  one  sifuafion  nor  in  the  other,  else  it  is  veiy  un  - 
likely that  such  correct  and  anxious  anatomists  should  have  described  that  valve  which  arises 
Irom  one  of  the  borders  of  the  oval  hole,  without  observing  it  open,  if  it  was  so ; especially  as 
the  oval  hole,  bdng  open,  is  by  no  means  an  nnusin!  occurrence. 


336 


OF  THE  MECHANISM 


ram  etiam  a Nichols  video  proponi.”  Of  the  truth  of  this 
theory  Haller  was  so  entirely  satisfied,  that  he  not  only  pub- 
lished it  as  peculiarly  his  own,  but  reclaimed  it  when  he  thought 
it  in  danger  of  being  thus  apprt>priated  by  another.  Sabatier 
is  the  last  in  the  train  of  authors  ; and  in  order  that  there  might 
remain  no  ambiguity  in  what  they  had  said  or  meant,  he  pro- 
nounces plainly  that  the  Eustachian  valve  is  useful  only  in  the 
fcetus,  and  that  there  are  two  opposite  currents  in  the  right 
auricle  of  the  heart;  that  the  one  goes  from  the  lower  cava 
upwards  to  the  foramen  ovale,  while  the  other  from  the  upper 
cava  descends  right  into  the  opening  of  the  ventricle.  What 
shall  we  say  to  anatomists,  who,  in  the  narrow  circle  of  the 
auricle,  conceive  two  currents  to  cross  each  other  directly,  and 
to  keep  as  clear  of  each  other  as  the  arrows  by  which  such 
currents  are  usually  represented.  This  error  in  reasoning  is 
below  all  criticism ; it  carries  us  backwards  a hundred  years 
in  anatomy  and  in  physics ; and  yet  this  is  alt  that  Winslow, 
Haller,  Sabatier,  and  a mob  of  others,  have  been  able  to  say 
in  proof  of  the  connection  of  the  Eustachian  valve  with  the 
circulation  of  the  fcetus. 

Lancisi,  again,  believed  that  it  was  chiefly  useful  by  support- 
ing the  blood  of  the  lower  cava,  defending  it  from  the  weight 
of  that  column  of  blood  which  is  continually  descending  from 
above ; and  Winslow  and.  others  approved  of  this,  as  being 
perhaps  one  use  of  the  valve.  But  they  have  all  of  them  for- 
gotten a little  circumstance,  which  must  afiect  the  office  of  the 
valve,  and  which  should  have  been  regarded  especially  by  those 
who  said  it  was  useful  chiefly  before  birth ; they  have  forgot- 
ten a little  circumstance,  which  John  Hunter  also  forgot,  when 
theorvzing  about  the  gubernaculum  testis,  viz.  that  the  child 
lies  with  its  head  downmost  for  nine  months  in  the  mother’s 
womb. 

Nothing  is  more  certain  than  that  the  Eustachian  valve  is 
not  peculiar  to  the  fcetus;  that  it  has  no  connection  with  the 
oval  hole  ; that  the  valve  is  often  particularly  large  after  the 
foramen  ovale  is  closed ; that  the  valve  is  often  obliterated 
where  yet  the  foramen  ovale  remains  open  ; that  in  adults  it  is 
more  easily  demonstrated  than  in  children ; that  in  old  age  it 
is  often  reticulated  as  the  other  valves  are.  Its  use  relates 
neither  to  the  foramen  ovale,  nor  to  the  ascending  cava  ; it  re- 
lates to  the  auricle  itself,  and  therefore  it  is  found  in  all  the 
stages  of  life,  smaller  or  larger,  according  to  the  size  or  form 
of  the  heart. 

The  auricle  on  the  side  towards  the  venae  cav®  is  imperfect; 
the  anterior  part  of  the  auricle  chiefly  is  muscular,  and  when  it 
contracts,  the  laxity  ofthecavas  and  the  great  width  of  the  sinus 


VOL.I/. 


Lriiry.  I'rll/pt . 


n.i  rj  thr  i^jiJar/nav  'Va! I'fi  . 


p.td. 


N”  10 


OF  THE  HEART. 


337 


VENOSDS,  {i.  e.)  of  almost  the  whole  auricle,  would  take  away 
from  its  contraction  all  effect ; but  to  prevent  this,  and  to  make 
the  auricle  perfect,  the  vena  cava  and  auricle  meet  so  oblique- 
ly, that  the  side  of  the  cava  makes  a sort  of  wall  for  the  auricle 
on  that  side.  This  wall  has  entirely  and  distinctly  the  reticu- 
lated structure  of  the  auricle  itself,  with  fleshy  bands  of  mus- 
cular fibres  in  it;  this  wall  falls  loosely  backwards  when  the 
auricle  is  quite  relaxed,  as,  for  example,  when  we  lay  it  open ; 
and  thus  it  has  got  the  appearance  and  name  without  the  uses 
of  a valve  ; but  when  the  heart  is  entire,  tense,  and  filled  with 
blood,  this  valve  represents  truly  a part  of  the  side  of  the  auri- 
cle : and  that  this  part  of  the  wall  of  the  auricle  should  be  oc- 
casionally a little  higher  or  lower,  looser  or  tenser,  we  need  not 
be  surprised.  This  further  may  be  observed,  that  wherever, 
as  in  a child,  this  valve  is  very  thin  and  delicate,  the  anterior 
part  of  the  fossa  ovalis  goes  round  that  side  of  the  auricle  par- 
ticularly deep  and  strong.  Let  it  also  be  remembered,  that 
in  certain  animals  this  valve  is  particularly  large  and  strong ; 
now,  in  a creature  which  goes  chiefly  in  a horizontal  posture,  it 
may  strengthen  and  make  up  the  walls  of  the  auricle,  (the  chief 
use  wiiich  I have  assigned  for  it  in  man ;)  but  surely  it  cannot- 
protect  the  blood  of  the  lower  cava  from  the  weight  of  blood 
coming  from  above,  since  the  body  of  an  animal  lies  horizon- 
tally, and  there  is  no  such  weight.  The  Parisian  academicians 
describe  the  heart  of  the  Castor  in  the  following  terms ; “ Un- 
der the  vena  coronaria  we  find  the  valve  called  nobilis  (viz. 
the  Eustachian  valve,)  which  fills  the  whole  trunk  of  the  vena 
cava,  and  which  is  so  disposed  that  the  blood  may  be  easily 
carried  from  the  liver  to  the  heart  by  the  vena  cava,  but  which 
is  hindered  from  descending  from  the  heart  towards  the  liver 
through  the  same  vein.”* 

* Eustachian  Valve. 

No.  14  explains  merely  the  placecf  the  Eustachian  valve,  which  is  seen  at  (m.)— No.  15. 
explains  both  * he  place  of  the  valve  and  its  relation  to  the  oval  hole  (e) — behind  it,  and  to 
the  month  of  the  ventricle  (n) — wliich  lies  before  it. 

In  both  these  plans— (o)  Is  the  cava  decendens — (6)  The  aorta  rising  behind  it — (cc) 
The  back  of  the  auricle  slit  open—  (d)  The  cava  ascendens,  in  the  mouth  of  which  the  valve 
IS — (e)^  The  foramen  ovale — (Jf)  Its  two  rising  borders,  named  pillars,  isthmus  of  Vieus- 
sens,  annulus  ovalis,  &c.  — (m)  The  Eustachian  valve,  of  which  the  two  cornua,  or  sharp 
Mints  are  .seen  in  the  lower  plate,  terminating  in  the  pillars  of  the  foi-amen  ovale  on  one 
hand,  and  in  the  walls  of  the  auricle  on  tae  otlier.  The  opening  of  the  foramen  ovale  (e) 
— is  behind  and  above  the  valve;  the  opening  into  the  right  ventricle  (n) — is  before  and 
under  the  valve. 

No  14.  erplains  more  particularly  the  uses  of  the  valve.  Some  authors  conceived  that 
it  directed  the  blood  rising  in  the  line  (o)— upwards  into  tho  ov  ,'iole : others  that  it  direct- 
ed tue  co'umn  of  blo.>J,  represented  by  the  arrow  (p)— into  tlie  right  ventricle;  otheisthat 
it  protected  the  column  (o)— from  the  weight  of  the  column  (?).—!  r;a  ler  suppose  that  it 
aompletes  the  auricle  in  the  direction  of  the  dotted  hue  (?)— and  so  strengthens  it?  action. 

VOI..  I.  U U 


338 


OF  THE  ACTION 


OF  THE  IRRITABILITY  AND  ACTION  OF  THE  HEART. 

But  even  this  curious  mechanism  of  the  heart  is  not  more 
Tvonderful  than  its  incessant  action,  which  is  supported  by  the 
continual  influx  of  stimulant  blood,  and  by  its  high  irritability 
and  muscular  power ; for  though  we  cannot  directly  trace  the 
various  courses  of  its  muscular  fibres,  there  is  not  in  the  human 
body  any  part  in  which  the  muscular  substance  is  so  dense  and 
strong.  In  the  heart  there  can  be  no  direct  or  straight  fibres ; 
for  let  them  go  off  from  the  basis  of  the  heart  in  what  direction 
they  may,  still  as  they  belong  to  the  one  or  the  other  ventricle, 
they  must  by  following  the  course  and  shape  of  that  ventricle, 
form  an  oblique  line.  Vesalius  has  not  indeed  represented 
them  so,  he  has  drawn  straight  fibres  only  ; because  in  the  lat- 
ter end  of  his  great  work  he  was  without  human  subjects,  and 
betook  himself  to  drawing  from  beasts. 

The  fibres  of  the  heart  are  all  oblique,  or  spiral,  some  lying 
almost  transverse  ; they  all  arise  from  a sort  of  tendinous  line 
which  unites  the  auricle  to  the  ventricle ; they  wind  spirally 
down  the  surface  till  the  fibres  of  the  opposite  ventricles  meet 
in  the  septum  and  in  the  apex  of  the  heart.  The  fibres  of 
each  ventricle  pass  over  the  convex  or  upper  surface  of  the 
heart,  then  over  the  apex,  and  then  ascend  along  the  flat  side 
of  the  heart,  which  lies  upon  the  diaphragm,  till  they  again 
reach  the  basis  of  the  heart.  The  second  layer  or  stratum  of 
fibres  is  also  oblique ; yet  many  of  the  fibres  run  almost  trans- 
versely, uniting  the  oblique  fibres ; but  when  we  go  down  into 
the  thick  substance  of  the  heart,  we  find  its  fibres  all  mixed, 
crossed,  and  reticulated  in  a most  surprising  manner;  so  that 
we  at  once  perceive  both  that  it  is  the  strongest  muscle  in  the 
body,  and  that  the  attempt  to  extricate  its  fibres  is  quite  ab- 
surd.* Their  desire  of  giving  more  correct  and  regular  des; 
criptions  has  been  the  cause  why  those  who  have  particularly 
studied  this  point  have  been  fatigued  and  disappointed ; the 
most  sensible  of  them  have  acknowledged  with  Vesalius,  Albi- 
nus,  and  Haller,  that  the  thing  could  not  be  done  ; while  those, 
again,  who  pretended  to  particular  accuracy,  and  who  have 
drawn  the  fibres  of  the  heart,  have  represented  to  us  such  ex- 
travagant, gross,  and  preposterous  things,  as  have  satisfied  us 
more  than  their  most  ingenuous  acknowledgments  could  have 
done,  that  they  could  also  could  accomplish  nothing. 

Tliickening  the  ivalls  of  the  heart  by  vinegar,  strong  acids,  alum,  or  boiling  the  heart, 
have  assisted  us  in  unrayelling  its  structure  but  very  little. 


OF  THE  HEAKT 


339 


There  is  no  question  that  irritability  is  variously  bestowed 
in  various  creatures,  that  it  is  variously  appointed  in  various 
parts  of  the  body,  that  this  property  rises  and  falls  in  disease 
and  health ; without  hesitation  we  also  may  pronounce  that  the 
heart  is  in  all  creatures  the  most  irritable  part ; it  is  the  part 
first  to  live  and  the  last  to  die  : “ Pulsus  et  vita  pari  ambulant 
passu.”  When  we  see  the  punctum  saliens  in  the  chick,  we 
know  that  there  is  life ; and  when  we  open  the  body  of  an 
animal  soon  after  death,  still  the  heart  is  irritable  and  con- 
tracts. 

In  the  very  first  days  in  which  the  heart  appears  in  the 
chick,  while  yet  its  parts  are  not  distinguished,  and  the  punc- 
tum saliens  is  the  only  name  vfe  can  give  it,  the  heart,  even  in 
this  state,  feels  the  slightest  change  of  heat  or  cold  ; it  is 
roused  by  heat,  it  languishes  when  cold,  it  is  excited  when 
heated  again.  It  is  stimulated  by  sharp  points  or  acids,  it 
works  under  such  stimuli  with  a violent  and  perturbed  motion. 
In  all  creatures  it  survives  for  a long  while  the  death  of  the 
body;  for  when  the  creature  has  died,  and  the  breathing  and 
pulse  have  long  ceased,  and  the  body  is  cold,  when  the  other 
muscles  of  the  body  are  rigid,  when  the  stomach  has  ceased 
to  feel,  when  the  bowels  which  preserve  their  contractile  pow- 
er the  longest  have  ceased  to  roll,  and  they  also  feel  stimuli 
no  more,  still  the  heart  preserves  its  irritability;  it  preserves 
it  when  torn  from  the  body  and  laid  out  upon  the  table ; heat, 
caustics,  sharp  points,  excite  it  to  move  again. 

We  know  also  another  thing  very  peculiar  concerning  the 
irritability  of  this  organ,  viz.  that  it  is  more  irritable  on  its  in- 
ternal than  on  its  externa]  surface ; for  if  instead  of  cutting 
out  the  heart,  we  leave  it  connected  with  the  body,  seek  out 
(as  the  old  anatomists  were  wont  lo  do)  the  thoracic  duct,  or 
pierce  any  great  vein,  and  blow  a bubble  of  air  into  the  heart, 
it  pursues  it  from  auricle  to  ventricle,  and  from  ventricle  to 
auricle  again,  till,  wearied  and  exhausted  with  this  alternate 
action,  it  ceases  at  last,  but  still  new  stimuli  will  renew  its 
force. 

Thus  it  is  long  after  apparent  drowning  or  other  suffocation 
before  the  principle  of  life  is  gone  ; and  long  after  the  death 
of  the  body  before  the  heart  be  dead;  and  just  as  in  this  pe- 
culiar part  of  the  system  irritability  is  in  high  proportion,  there 
are  in  the  scale  of  existence  certain  animals  endowed  in  a 
wonderful  degree  with  this  principle  of  life.  They  are  chiefly 
the  amphibious  creatures,  as  they  are  called,  needing  little  air, 
which  have  this  power  of  retaining  life  ; no  stimuli  seem  to 
exhaust  them,  there  seems  especially  to  be  no  end  to  the  action 


340 


OF  THE  ACTION 


of  their  heart;  a Newt’s  or  aToad’s  heart  beats  for  days  after 
the  creature  dies  : a Frog,  while  used  in  experiments,  is  often 
neglected  and  forgotten,  its  limbs  mangled,  and  its  bead  gone, 
perhaps  its  spinal  marrow  cut  across,  and  yet  for  a whole  night 
and  a day  its  heart  does  not  cease  beating,  and  continues  obe- 
dient to  stimuli  for  a still  longer  time.  It  seems  as  if  nothing 
but  the  loss  of  organization  could  make  this  irritable  muscle 
cease  to  act ; or  rather  it  seems  as  if  even  some  degree  of  de- 
ranged organization  could  be  restored  : breathe  upon  a heart 
which  has  ceased  to  act,  and  even  that  gentle  degree  of  heat 
and  moisture  will  restore  its  action.  Dr.  Gardiner  having  left 
a turtle’s  heart  neglected  in  a handkerchief,  he  found  it  quite 
dry  and  shrivelled,  but  by  soaking  it  in  tepid  water  its  plump- 
ness and  contractility  were  restored. 

Since,  then,  this  irritable  power  supports  itself  in  parts  long 
after  they  are  severed  from  the  body,  what  doubt  should  we 
have  that  there  is  in  the  muscular  fibre  some  innate  contractile 
power  or  vis  insita  independent  of  nerves.^  And  when  we  talk 
on  a subject  so  difficult  and  so  abstruse,  what  other  proof  can 
we  expect  or  wish  for,  than  the  power  of  one  peculiar  and  in- 
sulated muscle  surviving  the  separation  of  the  head  and  brain, 
the  destruction  of  its  nerves,  or  its  total  separation  from  that 
living  system  to  which  it  belongs?  If  the  heart  be  tlie  mbst 
irritable  muscle  of  the  body,  if  all  this  irritability  arise  from 
the  nerves,  how  can  it  be  that  this  muscle,  which  is  thus  an- 
nounced as  the  most  dependent  on  its  nerves,  is  really  the 
most  independent.^  that  the  muscle  which  of  all  the  body 
needs  this  nervous  supply  oftenest  should  want  it  the  least,  and 
should  survive  the  loss  of  its  nerves  so  much  longer  than  the 
other  muscles  of  the  same  body  ' 

Although  the  ancients  knew  how  irritable  the  heart  was, 
although  they  often  opened  living  creatures,  and  saw  the  heart 
struggling  to  relieve  itself,  because  it  was  oppressed  with  blood, 
yet  they  continued  entirely  ignorant  of  the  cause  : and  why  the 
heart  should  alternately  contract  and  relax  without  stop  or  in- 
terruption, seemed  to  them  the  most  inexplicable  thing,  in 
nature.  Hippocrates  ascribed  it  to  the  innate  fire  that  is  in  the 
heart ; Sylvius  said,  that  the  old  and  alkaline  blood  in  the 
heart  mixing  with  the  new  and  acid  chyle,  and  with  the  pan- 
creatic lymph,  produced  a ferment  there  ; Swammerdam, 
Pitcairn,  and  Friend,  thought  that  the  heart,  and  every 
muscle  which  had  no  antagonist  muscle,  was  moved  by  a less 
proportion  of  the  vital  spirit  than  other  muscles  required. 
Others  believed  that  each  contraction  of  a muscle  compressed 
the  nerves  of  that  muscle,  and  each  relaxation  relieved  it ; 


OF  THE  HEART. 


341 


and  that  this  altarnate  compression  and  relief  of  the  nerve 
was  the  cause  of  the  alternate  movements  of  the  heart: 
another  physician  of  our  own  country,  a great  mechanic,  and 
a profound  scholar  in  mathematics,  and  all  those  parts  of 
science  which  have  nothing  to  do  with  the  philosophy  of  the 
human  body,  refined  upon  this  theory  most  elegantly  ; for  ob- 
serving that  the  nerves  of  the  heart  turned  round  the  aorta, 
and  passed  down  betwixt  it  and  the  pulmonic  artery,  he  ex- 
plained the  matter  thus  : “ These  great  arteries,  every  time 
they  are  full,  will  compress  the  nerves  of  the  heart,  and  so 
stop  this  nervous  fluid,  and  every  time  they  are  emptied  (a 
thing  which  he  chose  to  take  for  granted,  for  in  truth  they 
never  are  emptied,)  they  must  leave  the  nerves  free,  and  let 
the  nervous  fluid  pass  down  to  move  the  heart.’’ 

Des  Cartes,  who  studied  every  thing  like  a right  philosopher 
of  the  old  breed,  viz.  by  conjecture  alone,  supposed  that  a 
small  quantity  of  blood  remained  in  the  ventricle  after  each 
stroke  of  the  heart : which  drop  of  blood  fermented,  became 
a sort  of  leaven,  and  operated  upon  the  next  blood  that  came 
into  the  heart,  “ like  vitriol  upon  tartar  so  that  every  suc- 
cessive drop  of  blood  which  fell  into  the  ventricle  swelled  and 
pufied  up  so  suddenly  as  to  distend  the  heart,  and  then  burst 
ont  by  the  aorta.  Philosophers  have  been  so  bewitched  with 
the  desire  of  explaining  the  phenomena  of  the  human  body, 
but  without  dihgence  enough  to  study  its  structure,  that  from 
Aristotle  to  Buffbn,  it  is  all  the  same,  great  ignorance  and 
great  presumption.  But  on  this  subject  of  the  pulse  of  the 
heart,  physicians  almost  surpassed  the  philosophers  in  the  ab- 
surdity of  their  theories,  till  at  last  they  were  reduced  to  the 
sad  dilemma  of  either  giving  up  speaking  upon  this  favourite 
subject,  or  of  contenting  themselves  with  saying,  “ that  the 
heart  beat  by  its  facultas  pulsifica,  its  pulsative  faculty  as  if 
they  had  said,  the  jaws  chew  by  their  mandicative  faculty, 
and  the  bladder  pisses  by  its  expulsive  faculty,  and  the  womb 
expels  children  by  its  parturient  pow'er. 

The  ancients,  I have  said,  often  opened  living  creatures, 
and  saw  the  heart  struggling  to  relieve  itself  because  it  was  op- 
pressed with  blood  : this  blood  is  itself  the  stimulus  which 
moves  the  whole ; for  important  as  this  function  is,  it  is  equally 
simple  with  all  the  others  : and  as  urine  is  the  stimulus  to  the 
bladder,  food  an  excitement  to  the  intestines,  and  the  full 
grown  foetus  a stimulus  to  the  womb  ! — so  is  blood  the  true 
stimulus  to  the  heart.  When  the  blood  rushes  into  the  heart, 
the  heart  is  excited  and  acts  ; when  it  has  expelled  that  blood, 
it  lies  quiescent  for  a time  ; when  blood  rushes  in  anew,  it  is 


342 


OF  THE  ACTION 


voused  again  : so  natural  is  both  the  incessant  action  and  regu- 
lar alternation  of  contraction  and  relaxation  in  the  heart. 

It  is  when  we  are  so  cruel  as  to  open  a living  creature  that 
we  see  best  both  the  operation  of  the  blood  as  a stimulus,  and 
the  manner  in  which  the  heart  re-acts  upon  it.  When  we  tie 
the  two  vena  cavas  so  as  to  prevent  the  blood  from  arriving  at 
the  heart,  the  heart  stops ; when  we  slacken  our  ligatures  and 
let  in  the  blood,  it  moves  again ; when  we  tie  the  aorta,  the 
left  ventricle  being  full  of  blood  will  continue  struggling, 
bending,  turning  up  its  apex,  and  contracting  incessantly  and 
strongly,  and  will  continue  this  struggle  long  after  the  other 
parts  have  lost  their  powers.  One  author,  whether  from  his 
awkwardness,  or  the  delicacy  of  the  subject,  or  really  from 
the  strength  of  the  ventricle,  assures  us,  that  often  while  he 
has  held  the  aorta  of  a Frog  close  with  pincers,  it  has  burst  by 
the  mere  force  of  the  heart.  If,  after  violent  struggles  of  this 
kind,  you  cut  the  aorta,  even  of  so  small  a creature  as  an  eel, 
it  will  throw  its  blood  to  the  distance  of  three  or  four  inches. 

Thus  we  not  only  know  that  we  can  excite  the  heart  by  ac- 
cumulating blood  in  it,  but  that  by  confining  the  blood  in  it 
we  can  carry  that  excitement  to  a very  high  degree  ; and  in 
short,  by  keeping  the  one  or  the  other  ventricle  incessantly 
full  of  blood,  we  can  make  the  one  heart  work  continually, 
while  the  other  lies  quiet,  or  is  only  slightly  drawn  by  the  other’s 
motion,  showing  the  true  distinction  betwixt  the  heart  of  the 
body  and  the  heart  of  the  lungs.  And  this  is  a memorable 
fact,  that  it  is  not  merely  the  stimulus  of  the  blood,  but  the 
sense  of  fulness  that  makes  the  heart  contract;  for  the  auricle 
often  beats  twice  or  thrice,  sometimes  it  makes  its  push  four 
or  five  times,  before  it  can  force  the  ventricle  to  contract. 

When  we  empty  the  heart,  and  tie  all  its  veins,  all  its  parts 
cease  to  act ; stimuli  applied  outwardly  make  it  contract  par- 
tially ; it  trembles  in  particular  fibres  : but  it  is  only  letting  in 
the  blood,  or  blowing  it  up  with  air,  that  can  bring  it  into  full 
action  again.  When  we  look  with  cruel  deliberation  upon  the 
strokes  of  the  heart  in  any  living  creature,  we  observe  that  at 
first,  during  the  full  and  rapid  action  of  the  heart,  there  is 
hardly  any  perceptible  interval  among  the  several  parts  ; but 
towards  the  end  of  each  experiment,  when  the  pulse  flags, 
and  the  creature  falls  low,  the  swelling  of  the  great  veins,  and 
the  successive  strokes  of  auricle  and  ventricle,  are  distinctly 
told.  The  dilatation  and  contraction  of  each  part  is  what  we 
cannot  observe,  they  are  so  quick ; but  these  things  we  dis- 
tinctly observe  : the  auricle  contracts  and  dilates  the  ventricle  ; 
the  ventricle  contracts,  subsides,  and  fills  the  aorta ; the  aorta 
turns  and  twists  with  the  force  of  the  blood  driven  into  it,  and 


OF  THE  HEART. 


343 


by  its  own  re-action,  and  the  ventricle,  every  time  that  it  con- 
tracts, assumes  a form  slightly  curved,  the  point  turning  up 
like  a tongue  towards  the  basis,  and  the  basis  in  some  degree 
bending  towards  the  point.  The  basis,  indeed,  is  in  some 
degree  fixed  to  the  diaphragm  and  spine,  but  the  heart  in  its 
contraction  always  moves  upon  its  basis  as  upon  a centre  ; its 
ventricles,  and  especially  its  apex,  are  free ; the  point  rises 
and  curves  so  as  to  strike  against  the  ribs  ; and  the  dilatation  of 
the  heart  is  such  (together  with  the  posture  and  relation  of  its 
several  parts,)  that  during  the  dilatation  the  heart  turns  upon 
its  axis  one  way ; the  contraction  of  the  heart  reverses  this, 
and  makes  it  turn  the  other  way,  so  that  it  seems  to  work  per- 
petually mth  the  turning  motions  of  a screw.  All  this  is  most 
striking,  while  we  are  looking  upon  the  motion  of  the  heart  in 
a living  creature. 

The  posture  of  the  human  heart  is  very  singular,  and  will 
illustrate  this  turning  motion  extremely  well ; for  in  the  hu- 
man heart  the  posture  is  so  distorted,  that  no  one  part  has 
that  relation  to  another  which  we  should  beforehand  expect. 
In  the  general  system,  the  human  heart  is  placed  nearly  in 
the  centre,  but  not  for  those  reasons  which  Dionis  has  assign- 
ed ; it  is  not  in  order  that  by  being  in  the  centre  it  may  feel 
less  the  difiiculty  of  driving  the  blood  to  any  particular  limb 
or  part  of  the  body;  it  is  the  place  of  the  lungs  that  regu- 
lates the  posture  of  the  heart ; and  wherever  they  are,  it  is. 
Except  the  Oyster,  I hardly  know  of  any  creature  in  which 
the  heart  lies  expressly  in  the  centre  of  the  body.  In  Frogs, 
Toads,  Newts,  and  Snakes,  tbe  lungs  are  not  moved  by  any 
diaphragm  ; they  are  filled  only  by  the  working  of  the  bag 
attached  to  the  lower  jaw,  the  lungs  then  begin  under  the 
jaws,  and  the  heart  is  lodged  at  the  root  of  the  jaws,  leaving, 
as  in  a Newt  or  Cameleon,  Crocodile,  Adder,  Serpent,  &c. 
the  whole  length  of  their  trailing  body  behind.  In  a fish, 
the  gills  serve  the  creature  for  lungs ; the  gills  are  lodged  un- 
der the  jaws,  and  the  heart  is  placed  betwixt  them.  In  in- 
sects, as  in  the  common  Caterpillar,  (the  aurelia  of  our  com- 
mon Butterfly,)  the  air  enters  by  many  pores  on  its  sides ; 
and  accordingly  its  heart  is  not  a small  round  bag,  but  may  be 
easily  seen  running  all  down  its  back,  working  like  a long 
aorta,  but  having  regular  pulsations,  denoting  it  to  be  the 
heart ; and  this  you  easily  see  through  the  insect’s  skin,  for  it 
is  more  transparent  along  the  back  where  the  heart  is. 

The  breast  in  man  is  divided  into  two  cavities  by  a mem- 
brane named  the  mediastinum.  This  membrane  passes  di- 
rectly across  the  breast  from  the  sternum  before  till  it  fixes 


344 


OF  THE  ACTION  OF  THE  HEART. 


itself  into  the  spine  behind.  It  is  on  the  left  side  of  this 
mennbrane,  in  the  left  cavity  of  the  breast,  that  the  heart  is 
placed,  lying  out  flat  upon  the  diaphragm,  as  upon  a floor,  by 
which  it  is  supported ; ^ and  that  surface  {a) — which  lies  thus 
upon  the  diaphragm,  is  perfectly  flat,  while  the  upper  sur- 
face (6) — or  what  we  usually  call  the  forepart  of  the  heart, 
is  remarkably  round.  The  whole  heart  lies  out  flat  upon  the 
diaphragm ; its  basis  (c) — where  the  auricles  are,  is  turned 
towards  the  spine  and  towards  the  riL,ht  side  ; the  apex  {d) — • 
or  acute  point  is  turned  foi  wards  and  a little  obliquely  towards 
the  left  side,  where  it  strikes  the  ribs ; the  vena  cava  (e) — 
enters  in  sueh  a manner  through  a tendinous  ring  of  the 
diaphragm,f  that  it  ties  down  the  right  auricle  to  that  floor 
(as  I may  term  it)  of  the  thorax  ; the  aorta  (/)  does  not  rise 
in  that  towering  fashion  in  which  it  is  seen  when  we  take  a 
dried-up  heart,  which  naturally  we  hold  by  its  apex,  instead 
of  laying  it  out  flat  upon  tbe  palm  of  our  hand  ; nor  in  that  per- 
pendicular direction  in  which  hitherto,  for  the  sake  of  distinct- 
ness, I have  represented  it  in  these  plans ; but  the  aorta  goes 
out  from  its  ventricle  towards  the  right  side  of  the  thorax ; it 
then  turns  in  form  of  an  arch,  not  directly  upwards,  but  ra- 
ther backwards  towards  the  spine ; then  it  makes  a third  twist 
to  turn  downwards ; where  it  turns  downwards  it  hooks  round 
the  pulmonic  artery,  (^) — just  as  we  hook  the  fore-fingers  of 
our  two  hands  within  one  another.  The  right  heart  \h1i) — 
stands  so  before  the  other,  that  we  see  chiefly  the  right  auricle 
and  ventricle  before,  so  that  it  might  be  named  the  anterior 
heart ; the  pulmonic  artery  [g) — covers  the  root  of  the  aorta; 
the  left  ventricle  {i,) — from  which  the  aorta  rises,  shows  little 
more  than  its  point  at  the  apex  of  the  heart ; the  left  auricle 
{k) — is  seen  only  in  its  very  tip  or  extremity,  where  it  lies  just 
behind  the  pulmonic  artery  ; and  the  aorta  (/) — arises  from 
the  very  centre  of  the  heart.  From  this  view  any  man  may 
understand  these  vessels  by  other  marks  than  the  mere  colours 
of  an  injection ; and  he  will  also  easily  understand  why  the 
heart  twists  so  in  its  actions,  and  how  it  comes  to  pass  that  its 
posture  is  difficult  for  us  to  conceive,  no  one  part  having  that 
relation  to  any  other  part  which  we  should  beforehand  sup- 
pose. 

* The  true  pasition  of  the  heart  is  what  is  represented  in  No.  16.  and  17. ; where  No. 

16.  shows  the  heart  set  upright,  as  I have  hitherto  represented  it  in’aU  my  plans,  while  No. 

17.  represents  its  inclined  position  lying  almost  horizontally  upon  the  floor  of  the 
diaphragm. 

t Let  it  be  observed,  that  (e)  in  this  drawing,  marks  the  jrtint  where  the  lower  cava  was 
tied  close  upon  the  diapliragm,  to  prevent  the  injection  going  down  into  the  veins  of  the 
liver  and  abdominal  cav». 


X.SrU  ilf! . J'.Mentrtck  A*. 


of  ///r.  Pcricordiiorii  of  vliitJi  ix  o true,  drawinfj/  If  19  aP]//,n 
shewi its  / /ifUxirjri-  ow.r  tt/j’,  Ife^rC 


I 

P.3,.  I 


OF  THE  PERICARDIUM. 


345 


OF  THE  PERICARDIUM. 

But  the  PERICARDIUM,  purse,  or  capsule,  in  which  the 
heart  is  contained,  affects  and  regulates  its  posture,  and  makes 
the  last  important  point  concerning  the  anatomy  of  the  heart. 
It  is  a bag  of  considerable  size  and  great  strength,  which 
seems  to  us  to  go  very  loosely  round  the  heart,  because  when 
we  open  tbe  pericardium,  the  heart  is  quite  empty  and  re- 
laxed ; but  I believe  it  to  surround  the  heart  so  closely  as  to 
support  it  in  its  palpitations,  and  more  violent  and  irregular 
actions  ; for  when  we  inject  the  heart,  its  pericardium  remain- 
ing entire,  that  bag  is  filled  so  full  that  we  can  hardly  lay  it 
open  with  a probe  and  lancet  without  wounding  the  heart ; 
and  still  further,  when  we  open  the  pericardium  before  we  in- 
ject the  heart,  the  heart  receives  much  more  injection,  swells 
to  an  unnatural  bulk  for  the  thorax  that  it  is  contained  in,  and 
loses  its  right  shape.  The  pericardium  is  formed,  like  the 
pleura  and  mediastinum,  of  the  cellular  substance  ; it  is  rough 
and  irregular  without,  and  fleecy  with  the  threads  of  cellular 
substance,  by  which  it  is  connected  with  all  the  surrounding 
parts ; within  it  is  smooth,  white,  tendinous,  and  glistening,  and 
exceedingly  strong.  As  the  heart  lies  upon  the  floor  of  the 
diaphragm,  the  pericardium,  which  lies  under  the  heart,  is 
connected  with  the  diaphragm  a little  to  the  left  of  its  ten- 
dinous centre,  and  so  very  strongly  that  they  are  absolutely 
inseparable.  The  pericardium  surrounds  the  whole  heart, 
but  it  is  loose  every  where  except  at  the  root  of  the  heart, 
where  it  is  connected  with  the  great  vessels  : for  the  pericar- 
dium is  not  fixed  into  the  heart  itself,  but  rises  a considerable 
way  upon  the  great  vessels,  and  gives  to  the  roots  of  the 
vessels,  which  are  seen  on  opening  the  pericardium,  an  out- 
ward coat,  and  surrounds  each  vessel  with  a sort  of  ring,  as 
may  be  seen  in  the  plan.*  For,  1st,  It  surrounds  the  pulmo- 
nic veins  where  they  are  entering  the  heart ; there  the  peri- 
cardium is  short : 2dly,  It  mounts  higher  upon  the  vena  cava 
than  upon  any  other  vessel ; the  cava  of  course  is  longer  with- 
in the  pericardium,  and  it  also  is  surrounded  with  a sort  of 
ring  : 3dly,  It  then  passes  round  the  aorta  and  pulmonic  ar- 
tery, surrounding  these  in  one  greater  loop  : 4thly,  The  cava 
inferior  is  the  vessel  which  is  the  shortest  within  the  pericar- 
dium : for  the  heart  inclines  towards  the  horizontal  direc- 
tion : it  lies  in  a manner  flat  upon  the  upper  surface  of  the 
diaphragm,  while  the  lower  surface  of  the  diaphragm  ad- 

* Vide  Plan,  No.  18. 

VOU.  I.  X X 


346 


OF  THE  PERICARDIUM. 


Iieres  to  the  upper  surface  of  the  liver.  Thus  it  happens  that 
the  liver  and  the  right  auricle  of  the  heart  are  almost  in  con- 
tact, the  diaphragm  only  intervening ; thence  the  lower  cava 
which  passes  from  the  liver  into  the  right  auricle  of  the  heart 
cannot  have  any  length.  While  the  pericardium  thus  passes 
round  the  great  vessels,  it  must  leave  tucks  and  corners ; and 
these  have  been  named  the  cohnua,  or  horns  of  the  peri- 
cardium. 

But  there  is  another  peculiarity  in  the  form  of  the  pericar- 
dium, which  I have  explained  in  this  second  plan;*  viz  that 
the  pericardium  constitutes  also  the  immediate  coat  of  the 
heart;  for  the  pericardium  having  gone  up  beyond  the  basis 
of  the  heart  so  as  to  surround  the  great  vessels,  it  descends 
again  along  the  same  vessels,  and  from  the  vessels  goes  over  the 
lieart  itself.  I have  marked  the  manner  of  this  more  delicate 
inflection  of  the  pericardium  at  (aa,) — where  the  pericardium 
is  loose  ; at  (6//,)  — the  angle  where  it  is  reflected  ; and  at  (cc,) 
— where  it  forms  the  proper  coat  of  the  heart,  and  where  it  is 
intimately  united  to  its  substance.  The  pericardium  where  it 
forms  this  coat  becomes  extremely  thin  and  delicate,  almost 
cuticular,  but  strong ; under  this  coat  the  coronary  arteries 
pass  along  in  the  cellular  substance  ; under  it  the  fat  is  gather- 
ed sometimes  in  a wonderful  degree,  so  as  to  leave  very  little 
to  be  seen  of  the  dark  or  muscular  colour  of  the  heart. 

The  pericardium  then  is  a dense  and  very  strong  membrane, 
which  I would  compare  with  the  capsule  of  any  great  joint, 
both  in  office  and  in  form  : for  it  is  rough  and  cellular  without, 
shining  and  tendinous  within;  bedewed  with  a sort  of  halitus 
like  the  great  joints,  though  perfect  yet  delicate  in  the  child, 
but  increasing  in  thickness  by  the  continual  frictions  of  the 
heart,  just  as  a capsular  ligament  does  by  the  working  of  its 
joint ; and  its  uses  are  to  keep  the  heart  easy  and  lubricated 
by  that  exhalation  which  proceeds  from  its  exhalent  arteries, 
(and  which  can  be  imitated  so  easily  by  injecting  tepid  water 
into  its  arteries)  to  suspend  the  heart  in  some  degree  by  its 
connections  with  other  parts,  especially  by  its  connections 
with  the  mediastinum  and  diaphragm.  The  pericardium 
limits  the  distention  of  the  heart,  and  checks  its  too  violent  ac- 
tions; just  as  we  see  it  prevent  too  much  of  our  injections  from 
entering  the  heart.  How  strong  the  pericardium  is,  and  how 
capable  of  supporting  the  action  of  the  heart,  even  after  the 
most  terrible  accidents,  we  know  from  this  : that  the  heart  or 
coronary  arteries  have  actually  burst,  but  with  a hole  so  small 
-as  not  to  occasion  immediate  loss  of  life  ; then  the  pericardium 

w. 


OF  THE  PERICARDIUM. 


347 


receiving  tbe  blood  which  came  from  the  rupture,  has  dilated 
in  such  a manner  as  to  receive  nine  or  ten  pounds  of  blood, 
but  bas  yielded  so  slowly  as  to  support  the  heart  in  some  kind 
of  action,  and  so  preserved  life  for  two  or  three  days. 

If  I have  not  mentioned  any  fluid  under  the  direct  name  of 
AQUA  PERICARDII,  ortlie  Water  of  the  pericardium,  it  is  because 
I consider  the  accident  of  water  being  found  as  belonging  not 
to  the  healthy  structure  but  to  disease.  Yet  this  same  water 
occupied  the  attention  of  the  older  authors  in  a most  ludicrous 
degree.  Hippocrates  believed  that  this  water  of.  the  pericar- 
dium came  chiefly  from  the  drink  we  swallow,  which  found 
some  way  or  other  (as  it  passed  by  the  pericardium)  to  insinu- 
ate itself  into  this  bag.  Some  after  him  said,  it  was  the  fat  of 
the  heart  melted  down  by  incessant  motion  and  the  heat  of  the 
heart ; some  said  it  was  from  humours  exuding  through  the 
heart  itself,  and  retained  by  the  density  of  the  pericardium,  that 
this  water  came ; and  it  is  but  a few  years  since  this  clear  and 
distinct  account  of  it  was  given,  viz.  “ that  it  proceeds  from  the 
aqueous  excrementitious  humour  of  the  third  concoction.”  The 
same  “ sad  and  learned  men,*  viri  graves  et  docti,”  declare 
to  us,  that  the  uses  of  the  aqua  pericardii  are  to  cool  the  heart, 
for  it  is  the  very  hottest  thing  in  the  body  ; or  by  its  acrimony 
to  irritate  the  heart,  and  support  its  motions  ; or  to  make  the 
heart  by  swimming  in  it  seem  lighter.  By  this  it  is  pretty  ob- 
vious what  absurd  notions  they  had  of  the  quantity  of  water 
that  may  be  found  in  the  heart.  But  of  all  the  outrages  against 
common  sense  and  common  decorum,  the  most  singular  was 
the  dispute  maintained  among  them,  whether  it  was  or  was 
not  the  water  of  the  pericardium  which  rushed  out  when  our 
Saviour’s  side  was  pierced  with  the  spear  ? The  celebrated 
Bardius,  in  a learned  letter  to  Bartholine,  shows  how  it  was 
the  water  of  the  pericardium  that  flowed  out ; but  Bartholine, 
in  his  replication  thereunto,  demonstrates,  that  it  must  have 
been  the  water  of  the  pleura  alone.  This  abominable  and  lu- 
dicrous question,  I say,  they  bandied  about  like  boys  rather 
than  men : Bartholinus,  Arius,  Montanus,  Bertinus  Nicelius, 
Fardovius,  Laurenbergius,  Chiprianus,  with  numberless  other 
Doctors  and  Saints,  were  all  busy  in  the  dispute ; for  which 
they  must  have  been  burnt  every  soul  of  them,  at  the  stake, 
had  they  done  this  in  ridicule ; but  they  proceeded  in  this 
matter  with  the  most  serious  intentions  in  the  world,  and  with 
the  utmost  gravity .f  The  whole  truth  concerning  water  in  the 

* They  are  thus  denominated  in  all  the  charters  of  the  College  of  Physicians  from  the 
time  of  Henry  VIII.  downwards. 

+ The  shocking  indecencies  of  their  reasonings  on  this  subi’ect  I will  not  condescend  to 
draw  out  from  the  obscurity  of  that  barbarous  idi«n  in  which  it  was  delivered : “ Sed  non 


348 


OF  THE  PERICARDIUM. 


pericardium  is,  that  you  find  water  there  whenever  at  any  time 
you  find  it  in  any  of  the  other  cavities  of  the  body.  If  a per- 
son have  laboured  uader  a continued  weakness,  or  have  been 
long  diseased,  if  a person  have  Iain  long  on  his  death-bed,  if  the 
body  have  been  long  kept  {ifter  death,  there  is  both  a conden- 
sation of  the  natural  halitus  in  all  the  parts  of  the  body,  and  an 
exudation  of  thin  lymph  fi  om  every  vessel ; there  is  water 
found  in  every  cavity,  from  the  ventricles  of  the  brain  to  ihe 
cavity  of  the  ankle-joint,  and  so  in  the  pericardium  among  the 
rest.  But  ifyouopen  any  living  animal,  as  a Bog.  or  if  you 
open  suddenly  the  body  of  a suicide,  or  a criminal  who  has 
been  just  hanged,  not  a drop  of  water  will  be  found  in  the  pe- 
ricardium. When  such  fluid  is  to  be  found,  it  is  of  the  same 
nature  with  the  dropsical  fluids  of  other  cavities  : in  the  child, 
and  in  young  people,  it  is  reddish,  especially  if  the  pericardium 
be  inflamed  ; in  older  people  it  is  pellucid,  or  of  a light  straw 
colour;  in  old  age  and  in  the  larger  animals  it  is  thicker,  and 
more  directly  resembles  the  liquor  of  a joint. 

Thus  does  the  pericardium  contribute  in  some  degree  to  set- 
tle the  posture  of  the  heart ; but  still  the  heart  is  to  a certain 
degree  loose  and  free.  It  is  fixed  by  nothing  but  its  great  ves- 
sels as  they  run  up  towards  the  neck,  or  are  connected  with  the 
spine ; but  how  slight  this  hold  is,  how  much  the  heart  must 
be  moved,  and  these  vessels  endangered,  by  shocks  and  falls, 
it  is  awful  to  think.  The  pericardium  is  no  doubt  some  re- 
straint : its  connections  with  the  diaphragm  and  wdth  the  me- 
diastinum, make  it  a provision,  in  some  degree,  against  any 
violent  shoek ; its  internal  lubricity  is,  at  the  same  time,  a 
means  of  making  the  heart’s  motions  more  free  : yet  the  heart 
rolls  about  in  the  thorax ; we  turn  to  our  left  side  in  the  bed, 
and  it  beats  there ; we  turn  over  to  our  right  side,  and  the 
heart  falls  back  into  the  chest,  so  that  its  pulse  is  no  where  to 
be  perceived ; we  incline  to  our  left  side  again,  and  it  beats 
quick  and  strong.  The  heart  is  raised  by  a full  stomach,  and  is 
pushed  upwards  in  dropsy  ; and  during  pregnancy  its  posture 
is  remarkably  changed ; it  is  suddenly  depx’essed  again  wiien 
the  child  is  delivered,  or  the  waters  of  a dropsy  drawn  olF;  It 
is  shaken  by  coughing,  laughing,  sneezing,  and  every  violent 
elfort  of  the  thorax.  By  matter  collected  within  the  thorax  it 

cogai-  hue  me  conferre.  Fateor  enim  nativam  Chiisli  temperiem  nihil  pravonim  huniorum 
produxissp,  quia  perfuctissima ; at  a eausis  externis,  vigiliis.cruciatibus,  itineribii?, '.  iirnci'i- 
busetmihe  tormentis  quid  non  prfeter  con  uetam  natura?  divinas  perfectionem  prorltictum 
erefiimuii  ? Ad  hire  sanosensu  id  aceifiienduiii,  nihil  pravoruin  huinorum  in  corpore  Cliiisti 
generatiiin.”  Bartholini  Epistola-,  p.  290.  “ Idque  de  Salvatore  innoxie  dixeiis',  quern 

^ciiiiT’.s  ;n  iidueasse,  hibisse,  dormivisse,  ainbulatse,  et  quid  non  egisse,  ut  se  lioinineni  mnetis 
actio  i'liT  qus  -ecundumnatui'amsunl,  fubinitteret  : sputum  emisit,  quum  Into  mtsceret  ad 
curaviiimn 't.'ou.'j,  et  sudavit  ing’uente  mai'tyrio,  et  sine  dubio  non  paiumseri  in  thorace 
collegit,  quod,  aperto  post  moideip  latere,  qmanavit.”  Bartholini  Ejnstolce.,  p.  300. 


OF  THE  PERICARDIUM. 


349 


may  be  displaced  to  any  degree.  Dr,  Farquharson  cured  a 
fine  boy,  about  eight  years  old,  of  a great  collection  of  matter 
in  the  chest,  whose  heart  was  so  displaced  by  a vast  quantity 
(no  less  than  four  pounds)  of  pus,  that  it  beat  strongly  on  the 
right  side  of  the  breast  while  his  disease  continued,  and  as 
soon  as  the  pus  was  evacuated,  the  beating  of  the  heart  re- 
turned naturally  to  the  left  side.  Who  could  have  believed 
that,  without  material  injury,  the  heart  could  be  so  long  and  so 
violently  displaced.^  Felix  Platerus  tells  us  a thing  not  so 
easily  believed,  that  a young  boy,  the  son  of  a printer,  having 
practised  too  much  that  trick  which  boys  have  of  going  upon 
their  bands  with  their  head  to  the  ground,  began  to  feel  ter- 
rible palpitations  in  the  left  breast ; these  gradually  increased 
till  he  fell  into  a dropsy  from  weakness,  and  died  ; and  upon 
dissecting  his  body,  the  situation  of  his  heart  was  found  to  have 
been  remarkably  changed  by  this  irregular  posture.  Now  we 
are  not  to  argue  that  such  change  of  posture  of  the  heart  couid 
not  happen  merely  frflm  this  cause,  because  professed  tumblers 
have  not  these  diseases  of  the  heart ; it  were  as  silly  to  argue 
thus  against  the  authority  of  Platerus,  as  to  say  that  every  post- 
boy has  not  aneurisms  of  the  ham,  or  that  every  chimney- 
sweeper has  not  a cancer  of  the  scrotum. 

We  may  now  close  this  chapter  on  the  mechanism  of  the 
heart ; in  which  all  the  parts  have  been  successively  explained. 
We  know  how  the  heart  is  suspended  by  the  mediastinum,  and 
by  its  great  vessels ; how  it  is  lubricated,  supported,  and  re- 
gulated in  its  motions,  by  the  pericardium  ; its  nerves,  which 
remain  to  be  explained  at  a fitter  time,  are  extremel}^  small, 
while  its  vis  insita,  or  irritability,  is  great  beyond  that  of  all  the 
other  parts.  We  can  easily  follow  the  circle  of  the  blood, 
which,  as  it  arrives  from  all  the  extremities,  irritates  the  auri- 
cle, is  driven  down  into  the  ventricle,  is  forced  thence  into  the 
pulmonic  artery,  pervades  the  lungs,  and  then  comes  round  to 
the  left  side  of  the  heart,  or  to  that  heart  w'hich  supplies  the 
body ; and  there  begins  a new  circulation,  called  the  greater 
circulation,  viz.  of  the  body,  as  the  other  is  called  the  lesser 
circulation  of  the  lungs.  Thus  we  recognise  distinctly  the 
functions  of  the  double  heart,  with  all  its  mechanism ; the 
stronger  heart  to  serve  the  body,  the  weaker  heart  to  serve  the 
lungs ; and  we  see  in  the  plainest  manner  two  distinct  functions 
performed  by  one  compound  heart : the  right  heart  circulates 
the  blood  in  the  lungs,  w'here  it  is  purified  and  renew-ed  ; the 
left  delivers  out  a quantity  of  blood,  not  such  as  to  fill  all  the 
vessels,  nor  such  as  to  move  onwards  by  this  single  stroke  of 
the  heart  to  the  very  extremities  of  the  body,  but  such  merely 
its  to  give  a sense  of  fulness  and  tension  to  the  vessels : the 


350 


OP  THE  HEART. 


force  Is  merely  such  as  to  excite  and  support  that  action  which 
the  arteries  every  where  perform  in  the  various  organs  of  the 
body,  each  artery  for  its  appropriated  purposes,  and  each  in 
its  peculiar  degree. 

By  understanding  thus  the  true  mechanism  and  uses  of  the 
heart,  we  can  conceive  how  the  ancients  were  led  into  strange 
mistakes,  by  very  simple  and  natural  appearances.  We  un- 
derstand why  Galen  called  the  right  auricle  the  “ ultimum 
“ moriens,”  or  the  part  which  died  last;  for,  upon  opening 
the  body  soon  after  death,  he  found  the  right  auricle  filled  with 
blood,  and  still  palpitating  with  the  remains  of  life,  when  all 
the  other  parts  seemed  absolutely  dead ; and  if  the  blood  al- 
ways accumulates  on  the  right  side  of  the  heart  before  death, 
-it  is  plain  that  the  stimulus  of  that  blood  will  preserve  the  I’e- 
mains  of  life  in  the  right  side,  after  all  appearance  of  life  on 
the  left  side  is  gone.  But  the  cause  of  this  accumulation  of 
blood  in  the  right  side  is  very  ill  explained  by  Haller,  though  it 
seems  to  have  employed  his  thoughts  during  half  his  life.  He 
says,  that  in  our  last  moments  we  breathe  with  difficulty  ; the 
lungs  at  last  collapse,  and  cease  to  act ; and  when  they  are  col- 
lapsed, no  blood  can  pass  through  them,  but  must  accumulate 
in  the  right  side  of  the  heart.  That  there  is  really  no  such 
collapse  of  the  lungs,  I propose  hereafter  to  show ; but,  in 
the  meanwhile,  this  is  the  true  reason,  viz.  that  when  the 
ventricles  of  the  heart  cease  to  act,  and  the  beating  of  the 
heart  subsides,  the  two  auricles  lie  equally  quiet,  but  in  very 
different  conditions ; the  right  auricle  has  behind  it  all  the 
blood  of  the  body  pouring  in  from  all  parts  during  the  last 
struggles ; but  the  left  auricle  has  behind  it  nothing  but  the 
empty  veins  of  the  lungs ; nothing  can  fill  it  but  what  fills  the 
vessels  of  the  lungs ; or,  in  other  terms,  nothing  can  fill  the 
left  auricle  but  the  stroke  of  the  heart  itself:  but  instead  of 
acting  the  heart  falls  into  a quiescent  state,  the  left  auricle  re- 
mains empty,  while  the  blood  oozes  into  the  right  auricle  from 
all  the  extremities  of  the  body  till  it  fills  up. 

Nothing  is  more  agreeable  than  to  find  such  phenomena 
described  faithfully  long  before  the  reason  of  them  is  under- 
stood. In  the  Parisian  dissections  I find  the  following  des- 
cription : “ When  the  breast  of  a living  Dog  is  opened  by 
taking  away  the  sternum,  with  the  cartilaginous  appendices  of 
the  ribs,  the  lungs  are  observed  suddenly  to  sink,  and  after- 
wards the  circulation  of  the  blood  and  the  motion  of  the 
heart  to  cease.  In  a little  time  after  that  the  right  ventricle  of 
the  heart  and  the  vena  cava  are  swelled,  as  if  they  were  ready 
to  burst.”*  This  was  what  deceived  the  ancients,  and  was  the 

» Page  261. 


OF  THE  HEART. 


351 


cause  of  all  their  mistakes.  When  they  found  the  right  ven- 
tricle thus  full  of  blood,  they  conceived  that  it  alone  conveyed 
the  blood  ; they  found  the  left  ventricle  empty,  and  believed 
that  it  contained  nothing  but  vital  spirits  and  air ; and  so  far 
were  they  from  having  any  notions  of  a circulation,  that  they 
thought  the  air  and  vital  spirits  went  continually  forwards  in  the 
arteries ; that  the  gross  blood  which  \vas  prepared  in  the  liver 
came  up  to  the  heart  to  be  perfected,  and  went  continually 
forwards  in  the  veins,  or,  if  they  provided  any  way  of  return 
for  these  two  fluids,  it  was  by  supposing  that  the  blood  and 
spirits  moved  forwards  during  the  day-time,  and  backwards 
in  the  same  vessels  daring  the  night. 

These  things  next  explain  to  us  why  they  called  the  right 
ventricle  ventriculus  sanguineus  ; they  found  it  full  of 
blood,  and  thought  its  walls  were  thinner,  because  it  had 
only  to  contain  the  very  grossest  parts  of  the  blood ; and  why 
they  called  the  left  ventricle  ventriculus  spirituosus  and 
NOBiLis  because  they  saw  it  empty,  and  concluded  that  it  con- 
tained the  animal  spirits  and  aerial  parts  of  the  blood,  and  its 
walls  were  thicker,  they  said,  to  contain  these  subtile  spirits- 
They  explain  to  us  their  names  of  arteria  venosa  and  vena 
ARTERiosA  ; for  they  would  have  veins  only  on  the  right  side 
of  the  heart,  and  arteries  only  on  the  left ; and  although  they 
saw  plainly  that  the  pulmonic  artery  was  an  artery,  they  called 
it  Arteria.  Venosa  : and  although,  on  the  left  side  again,  they 
saw  plainly  that  the  pulmonic  vein  was  merely  a vein,  they 
would  still  cheat  themselves  with  a name,  and  call  it  Vena  Ar- 
teriosa : the  veins,  they  said,  were  quiet,  because  they  con- 
tained nothing  but  mere  blood  ; the  arteries  leaped,  they  said, 
because  they  were  full  of  the  animal  spirits  and  vital  air. 

The  very  name  and  distinction  of  arteries  which  -we  now  use, 
arise  from  this  foolish  doctrine  about  air  and  animal  spirits. 
To  the  oldest  physicians  there  was  no  vessel  known  by  the 
name  of  artery,  except  the  aspera  arteria;  and  it  was 
named  Artery  becausfe  it  contained  air ; so  that  Hippocrates, 
when  he  speaks  of  the  carotids,  never  names  them  arteries, 
but  calls  them  the  leaping  veins  of  the  neck.  But  when 
Eristratus  had  established  his  doctrine  about  the  vessels  which 
go  out  from  the  heart,  carrying  vital  spirits  and  air,  the  name 
of  artery  was  transferred  to  them  ; and  then  it  was  that  the  an- 
cients began  to  call  the  vessels  going  out  from  the  left  side  of 
the  heart,  arteries,  naming  the  aorta  the  arteria  magna  and 
the  pulmonic  vein  the  ap.teria  venosa. 

When  a vein  was  cut,  they  saw  nothing  but  gross  blood, 
and  of  a darker  colour ; but  when  an  artery  was  cut,  they 
observed  that  the  blood  was  red ; that  it  was  full  of  air  bub  - 


3.52 


OF  THE  HEAni. 


bles ; that  it  spurted  out,  and  was  full  of  animal  spirits ; and 
thus  it  became  easy  for  them  to  show  how  safe  it  was  to  open 
a vein  where  nothing  was  lost  but  gross  blood,  how  terribly 
dangerous  it  was  to  open  an  artery  which  was  beating  with 
the  spirit  of  life;  and  this  they  considered  as  such  an  awful 
difference,  that  when  arteriotomy  in  the  temple  was  first  pro- 
posed. they  pronounced  it  murderous,  and  on  this  reasoning 
it  was  absfilutely  forsaken  for  many  ages. 

But  the  oldest  of  our  modern  physicians  soon  found  a ne- 
cessity of  mixing  this  blood  and  animal  spirits  together,  and 
for  a long  while  could  hit  on  no  convenient  way  by  which 
this  mixture  might  be  effected  : as  a last  shift,  they  made  the 
blood  exude  through  the  septum  of  the  heart ; and  then  the 
current  doctrine  was,  that  of  the  blood  which  came  from  the 
liver,  one  half  went  into  the  pulmonic  artery  to  nourish  the 
lungs  : the  other  half  exuded  through  the  septum  of  the  heart, 
to  mix  with  the  animal  spirits.  Riolanus  was  the  bitter  enemy 
of  Harvey  and  of  his  noble  doctrine  ; and  this  is  the  misera- 
ble and  confused  notion,  not  to  call  it  a doctrine,  which  he 
trumpeted  through  Europe  in  letters  and  pamphlets.  To 
make  good  this  miserable  hypothesis,  Riolanus,  Gassendus, 
and  many  others,  saw  the  necessity  of  having  side  passages 
through  the  septum  of  the  heart.  I really  believe  from  their 
mean  equivocating  manner  of  talking  about  these  passages, 
that  they  had  never  believed  them  themselves.*  “ The 
chyle,”  says  Bartholine,  “ and  the  thinner  blood,  passes 
through  the  septum  of  the  heart,  when  the  heart  is  in  systole 
and  the  pores  and  passages  are  enlarged.”  Thus  did  the 
celebrated  Bartholine  believe  the  septum  perforated.  Wal- 
Ifeus,  and  Merchetti,  and  Mollinettus  and  Monichen,  believed 
it,  and  Mr.  Broadbecquius  of  Tubingin  proved  it.f  But  I 
believe  most  potently  with  Haller,  that  whenever  they  wanted 
to  show  those  perforations,  they  managed  their  probes  so  as 
to  make  passages  as  wide  and  as  frequent  as  the  occasion  re- 
quired : “ Solebant  foramina  parare  adigendo  stylos  argenteos 
in  resistens  septum,”  says  Haller;  and  this  is  a full  and  true 
account  of  all  the  authors  who  have  described  side  passages 
through  the  septum  of  the  heart ; they  needed  them,  and 
they  made  them. 

Amidst  all  this  ignorance,  we  cannot  wonder  that  a thou- 
sand childish  imaginations  prevailed,  nor  that  the  qualities  of 
the  mind  were  deduced  from  the  physical  properties  of  the 

* That  1 may  not  seem  to  speak  too  liarshly  of  this  knot  of  conspirators  against  Harvey, 

I will  quote  what  Boerhaave  says  of  Riolanus,  who  was  at  the  head  of  them ; “ Non  ipse 
callidus  cavillationura  artifex  Riolanus,”  &c. 

t Experimento  perforatum  ostendit  Broadbecquius  Tubinga;, 


OF  THE  HEART. 


353 


heart.  We  have  heard  the  vulgar,  for  example,  speak  of  the 
bone  of  the  heart.  And  from  whom  did  this  arise  ? From 
Aristotle  ! who  explains  to  us,  that  there  is  at  the  root  of  the 
heart  a bone  which  serves  for  its  basis;  and  not  a physician 
has  written  upon  the  heart  since  his  time  who  has  not  spoken 
more  or  less  mysteriously  about  this  bone  ; while  in  truth  the 
whole  story  means  nothing  more  than  this,  that  where  the 
basis  of  the  arteries  are  fixed  into  the  hard  ring  or  basis  of 
the  heart,  the  place  is  extremely  firm,  almost  cartilaginous, 
especially  in  old  age,  when  often  the  roots  of  the  arteries 
are  ossified  or  converted  into  what  anatomists  have  chosen  to 
call  bone. 

Often  also  we  have  heard  the  vulgar  talk,  not  figuratively, 
but  in  the  plain  sense  of  the  words,  of  a little  or  big  heart,  as 
synonymous  with  a timorous  or  courageous  heart.  But  when- 
ever we  hear  mistakes  of  this  kind  among  the  vulgar,  w’e  may 
be  assured  they  have  some  time  or  other  come  from  high 
authority.  Bartholine  was  so  much  convinced  that  a small 
heart  begot  courage,  and  a great  one  irresolution  and  fear, 
that  he  is  thoroughly  surprized  when  he  finds  the  contrary; 
“ Cor  vastus  fuit  homo,  tamen  audax  fuerat,  ut  cicatrices  in 
capite  frequentes  et  rimss  in  cranio  testabantur.”  But  if  Bar- 
tholine be  right,  Kirkringius  is  quite  wrong,  and  has  mistaken 
the  doctrine;  for  he  says,  “An  magnanima  fuerit  h^ec  niagni 
cordis  foemina,  nescio,”  &c.  “ I do  not  know  whether  this  wo- 

man’s courage  was  as  big  as  her  heart;  but  this  I do  know, 
that  she  was  a famous  toper.  Whether  this  drinking  dilates 
the  heart,  and  makes  your  staunch  drinkers  such  famous  fight- 
ers, I cannot  pretend  to  decide.”  We  have  heard  the  vulgar 
talk  also  of  a hairy  heart,  as  familiarly  as  of  a hairy  man,  be- 
ing the  mark  of  high  courage  and  strength  ; but  what  shall 
we  think  of  it,  when  we  find  that  this  report  is  to  be  deduced 
fairly  from  Pliny,  through  the  most  celebrated  names  among 
our  old  physicians  He  it  was  who  began  with  telling  bow 
the  Messenians,  that  unhappy  people,  who  lived  for  so  m my 
ages  the  slaves  or  helots  of  Greece,  lost  their  great 
general  Aristomenes.  But  how  great  he  was,  never,  accord- 
ing to  Pliny,  came  to  be  known  till  after  his  death  ; for  the 
Lacedemonians  having  catched  him  three  limes,  resolved  at 
last  to  open  his  breast;  and  there  as  a proof  of  his  most  in- 
vincible courage  and  daring,  they  found  his  heart  filled  with 
hair.  This  from  Pliny  was  nothing,  if  such  dissections  bad 
not  been  made  since  then  an  hundred  times.  “ There  was  a 
robber,  (says  Benivinius,)  one  Jacobus,  who  having  beeii  taken 
down  from  the  gibbet  apparently  dead,  but  really  having  in 
him  the  remains  of  life,  was  laid  carefully,  recovered,  was 
VOL.  j.  Y y 


354 


OF  THE  HEART. 


perfectly  restored,  betook  himself  to  his  old  ways  again  ; and 
so  in  the  natural  course  of  things  came  round  to  his  old  mark 
the  gallows,  and  was  this  time  very  thoroughly  hanged. 
Wondering  (says  Benivinius)  at  the  perfect  wickedness  of  this 
man,  I longed  very  anxiously  to  dissect  the  body,  and  I actu- 
ally found  the  heart,  not  covered,  but  (refertum  pilis)  crammed 
with  hair.” 

But  there  is,  in  fact,  no  end  of  wonders  and  wonderful  dis- 
sections among  these  robbers  of  his.  His  next  subject  was 
not  a bold  robber,  but  a poor  sneaking  thief  (de  corde  furis 
cujusdam  ;)  there  was  no  hair  to  be  expected  in  his  heart ; but 
as  he  was  a thief  only,  it  was  consistent  with  this  doctrine  that 
he  should  be  first  very  heartless  ; secondly,  have  very  little 
brain ; thirdly,  that  he  should  have  very  inordinate  appetites 
and  desires.  Now  there  was  first  a great  two-legged  vein 
carrying  the  atrabilis,  the  source,  no  doubt,  of  all  his  inordi-  ■ 
nate  cravings,  directly  into  to  stomach.  Secondly,  there  was 
a great  abscess  full  of  pus  wasting  the  left  side  of  his  heart ; 
and,  thirdly  and  lastly,  the  back  part  of  the  head  (which  all  I 

the  anatomists  of  that  time  knew  very  well  was  the  seat  of  j 

memory)  was  in  him  so  small  that  it  could  hardly  contain  a j 

spoonful  of  that  kind  of  brain  ; and  this  want  was  the  reason  | 
(having  so  little  memory)  that  he  was  so  persevering  a thief;  i 

for  let  you  whip  him,  banish  him,  clap  him  in  the  stocks,  he  j 

forgot  it  straightway,  and  was  back  at  his  old  tricks  again,  like  j 

a dog  to  his  vomit.*  | 

But  these  are  now  almost  forgotten,  though  perhaps  the  ,[ 

history  of  the  absurdities  of  the  human  genius  should  no  n)ore  ji 

be  neglected  than  of  its  beauties.  Is  it  not  delightful  to  feel,  1 

that  after  floating  in  this  ocean  of  conjecture,  after  all  these 
disorderly  and  wild  dreams,  we  are  come  to  have  an  idea  of  i; 

the  heart,  simple  and  beautiful;  of  a heart  containing  within  | 

itself  two  functions;  first,  the  otfice  of  renewing  the  blood  ; | 

secondly,  the  office  of  animating  the  arteries,  and  by  them  S 

preserving  in  life  and  action  the  whole  system  of  the  body  ? 
These  are  the  two  offices  which  I shall  now  proceed  to 
explain. 

ii 

* “ Non  videntur  silentio  esse  pratereunda,  quse  nuper  in  inciso  Jacobi  cujusdam  furis  J 
insignis  cadavere  annotavimus : hifurcatarn  scilicet  venam  quae  a lieue  ad  ventriculum  atram  i 
defert  bilem,  turn  et  ahscessum  in  sinistro  cordis  ventre  pituita  redundantem;  postiemo  et 
posteriorem  ejus  capitis  partem,  uhi  memoiiae  sedes  est,  adeo  brevem,  ut  tantillam  cerebri  ' 
portiunculam  contineret.  Quam  oh  causam,  cum  priorum  scelerum  et  eorum  quae  pro  his 
saepe  passus  fuerat,  tormenta  scilicet,  exilia  et  carceres  initiime  recordaretur,  toties  ad  vo~ 
mitum  tanquani  canis  impudens  reversus  est,  ut  in  laqueum  tandem  incident,  vitseqiie  ae 
fttrti  finem  fecei'it.” — Vid.  Bmwinins. 


( 355  ) 


CHAP.  II. 

t~S  THE  APPEARANCE  AND  PROPERTIES  OP  THE  BLOOD,  Olj 

THE  CHEMISTRY  OF  OUR  FLUIDS,  AND  ON  THE  INFLUENCE 

AVHICH  AIR  HAS  UPON  THEM. 

By  the  simplest  methods  the  blood  can  be  resolved  into 
various  parts,  but  chiefly  into  these  three  ; the  red  globules, 
which  give  colour  to  the  blood  ; the  gluten,  which  gives  con- 
sistency and  nutritious  qualities  to  the  blood ; and  the  serum, 
which  dilutes,  mixes,  and  suspends  the  whole. 

Though  the  serum  and  gluten  did  not  pass  entirely  unnoticed, 
the  red  globules  were  the  part  of  the  blood  which  first  excited 
the  attention  of  physicians,  and  seemed  to  promise  a rich  har- 
vest of  discoveries  ; a promise  which  too  surely  never  was  ful- 
filled. The  red  particles  have  always  appeared  important,  be- 
cause they  seem  to  give  the  colour,  the  useful  qualities,  and 
the  whole  character  to  the  blood.  It  is  by  the  rolling  of  the 
red  particles  only  that  we  see  the  circulation  in  the  micros- 
cope ; it  is  red  blood  only  that  we  ever  name  as  blood  ; and 
the  colour  of  the  red  blood  changes  in  health  and  disease. 
But  when  physicians  studied  this  part  alone,  when  they  gave 
it  the  mark  of  chief  importance,  and  annexed  to  it  alone  the 
name  of  blood,  they  little  thought  how  far  they  over-rated 
its  importance,  how  far  the  red  particles  are  from  nourish- 
ing the  system,  from  being  essential  to  the  blood,  from  being 
universal  in  all  creatures.  They  bad  not  considered  what 
myriads  of  animals,  great  as  well  as  small,  want  the  red  par- 
ticles, and  (if  these  red  particles  are  to  be  the  characteristic) 
want  blood  ; while  philosophers  of  less  contracted  notions 
have  continued  to  call  that  fluid  blood,  which  fills  the  vessels 
of  plants. 

The  Harveian  doctrine  had  no  sooner  produced  a revolu- 
tion in  the  general  doctrines  of  physiology,  or  physicians  be- 
gun to  think  of  the  heart  and  its  circulation,  of  the  great  ar- 
teries, and  extreme  vessels,  of  the  difference  betwixt  arteries 
and  veins,  and  of  the  ways  in  which  the  fluids  move  through 
the  smaller  tubes  (for  they  saw  them  moving  by  their  micros- 
copes;) no  sooner  did  all  these  phenomena  and  new  wonders 
present  themselves  to  their  imaginations,  than  they  thought 
also  of  curious  ways  by  which  these  motions  and  secretions 
might  be  explained.  They  then  began  to  estimate  the  calibres 


356 


OF  THE  BLOOD. 


of  the  arteries,  to  calculate  with  great  affectation  of  care  the 
shape,  the  size,  the  composition,  as  they  choose  to  call  it,  of 
the  particles  of  the  blood  ; chimeras  and  fancies  sprung  up 
innumerable ; and  it  happened  unfortunately  that  for  a long 
while  physicians  studied  nothing  but  angles,  and  logarithms, 
and  algebraical  equations ; they  reasoned  according  to  those 
sciences  only  which  have  no  connection  with  the  physiology 
of  the  animal  body ; they  calculated  the  force,  the  thickness, 
the  dimensions  of  the  heart ; the  diameter,  and  the  strength 
of  walls,  and  the  direction  of  the  aorta ; their  experiments 
consisted  in  fixing  clumsy  tubes  into  the  arteries,  or  in  calcu- 
lating the  whole  quantity  of  blood  by  bleeding  an  animal  to 
death  ; they  applied  nothing  but  the  laws  of  hy'draulics,  {i.  e.) 
of  fluids  rising  and  falling  in  rigid  tubes,  to  explain  the  active 
arteries  of  a living  body  : in  short,  in  explaining  the  living 
body  they  forgot  that  it  was  alive.  But  now  the  age  of  infal- 
lible proofs  and  demonstrations  has  passed  over,  and  the  works 
of  Keill,  Pitcairn,  Borelli,  are  quite  neglected. 

This  disordered  and  miserable  state  of  science,  which  con- 
tinued for  a century  nearly,  arose  from  those  red  particles  of 
the  blood  engrossing  too  much  attention,  and  from  their  being 
allowed  an  importance  which  does  not  belong  to  them;  al- 
though one  must  still  acknowledge  that  they  are  very  sur- 
prising, because  they  are  very  unaccountable,  at  least  1 do 
not  know  that  any  natural  or  likely  use  for  them  has  been  yet 
assigned. 

Leeuwenhoek,  looking  through  his  glasses,  saw  that  this 
which  gave  the  red  colour  was  the  most  permanent  character- 
istic part  of  the  blood  ; he  saw  that  this  part  consisted  of  red 
particles  floating  in  the  serum  ; he  found,  or  pretended  to  find, 
that  they  were  of  the  same  size  in  a man  as  in  a fo  tus ; in  a 
chick  as  in  a hen ; in  a whale  or  elephant,  he  found  them  the 
same  as  in  a mouse  or  minnow  ; merely  because  it  was  con- 
venient for  him  to  find  it  so. 

But  poring  still  longer  over  these  particles,  he  perceived 
that  the  great  globules  were  so  far  imperfect  as  often  to  break 
in  pieces,  and  roll  about  in  the  serum  in  separate  parts ; and 
he  always  found  that  there  were  six  less  parts  composing  the 
greater  globule  of  the  blood.  By  looking  more  and  more,  he 
pretended  to  observe,  that  these  smaller  parts  into  which  (he 
red  globules  broke  down  still  preserved  their  form ; that  these 
were  the  particles  of  the  serous  part  of  the  blood;  and  that 
the  great  or  red  particles  frequently^  broke  dov/n  into  serous 
particles,  and  these  again  as  frequently  united  and  composed 
afresh  a red  globule.  He  pretended  to  find,  that  exactly  six 
smaller  globules  went  to  make  up  one  great  one ; and  he 


OF  THE  BLOOD.  357 

called  the  red  and  serous  globules  the  globules  of  the  first  and 
second  order. 

By  this  notion  of  orders  it  was  plain  that  he  intended  to 
plunge  deeper  into  this  hypothesis,  and  to  have  at  least  a third 
and  fourth  order ; besides,  these  orders  and  particles  were  at 
his  call,  he  might  do  as  he  pleased ; and  he  was  almost  the 
only  person  possessed  of  glasses  which  could  enable  the  physi- 
ologist to  see  and  tell  about  them.  He  pored  till  he  believed, 
or  at  least  made  others  believe,  that  he  saw  globules  of  a third 
order,  six  times  smaller  than  the  serous  globules,  and  of  course 
thirty-six  times  smaller  than  the  red  globules.  And  thus  he 
had  lymphatic  particles,  six  of  which  made  up  one  serous 
particle ; and  serous  particles,  six  of  which  niade  one  red 
globule. 

To  the  geometrical  physiologists  of  that  day  all  this  in- 
struction concerning  the  structure  of  the  blood  was  most  de- 
lightful ; it  corresponded  very  notably  with  their  calculations 
about  regularly  descending  series  of  vessels ; and  a most 
curious  method  did  they  find  out  for  settling  this  law  of  the 
branching  of  arteries.  They  took  the  plates  of  Eustachius, 
measured  with  compasses  the  arteries  and  veins,  estimated  the 
angles  at  which  each  branch  goes  off,  compared  the  several 
branches  with  the  parent  trunk;  and  from  such  calculations 
they  settled  the  general  law  as  heartily  and  freely,  as  if,  in- 
stead of  the  most  extravagant  plates  in  all  anatomy,  they  had 
been  measuring  actually  the  human  body  itself.  Thus  they 
had  set  up  their  doctrine  of  angles,  branches,  anastomoses, 
trunks,  and  extreme  vessels : they  had  found  that  there  was  a 
a regular  series  of  descending  arteries;  they  had  a tube  now 
suited  to  every  descending  particle  that  Leeuwenhoek  could 
invent : and  when  a particle  had  got  into  a wTong  vessel,  it 
could  go  back  till  it  found  a tube  that  suited  it : or  if  driven 
into  a wrong  bore,  it  could  break  itself  down  into  serous  or 
lymphatic  particles.  But  when  many  particles  did  stick  hard 
in  the  straight  places,  then  there  was  an  error  loci : then  the 
big  particles  were  out  of  their  peculiar  vessels,  and  then  the 
part  began  to  be  red:  thence  came  inflammations,  fevers, 
deeper  obstructions  : and  from  such  causes,  or  from  the  break- 
ing down  of  the  bood  and  humours,  came  every  disease  that 
could  be  named. 

So  very  greatly  were  they  delighted  with  the  discovery,  that 
Dr.  Martin,  who  had  measured  the  vessels,  as  I have  just  told, 
and  had  dreamt  over  this  the  longest  and  soundest  of  them  all 
speaks  of  it  in  these  rapturous  terms.  “ But  we  are  moreover 
certain  from  the  observations  of  that  most  Accurate  and  curious 
observer  of  the  minima  naturas,  that  there  are  innumerable 


35B 


OF  THE  BLOOW. 


vessels  of  such  a smallness  that  none  of  these  globules  eould 
pass;  so  that  it  is  necessary  to  suppose  inferior  classes  of 
globules  of  the  fourth,  fifth,  sixth,  and  other  orders. — Whence 
by  analogy  we  are  to  conceiv'e  globules  of  the  third  order  made 
up  of  six  globules  of  the  fourth  order,  and  these  of  six  of  the 
fifth  order,  and  so  on  ad  infinitum  through  various  degrees,  the 
number  of  which  we  are  not  to  take  upon  us  to  determine.” 
This  is  a pleasant  addition  of  Dr.  Martin’s ; and  makes  it  a most 
manageable  system  of  most  dilatable  materials,  stretching  so 
as  to  suit  all  occasions.  This  rider  or  codicil  to  the  doctrine 
made  it  easy  for  every  particle  to  pass  every  vessel ; but,  alas ! 
it  leaves  no  room  for  that  old  catchword  of  the  system,  the  er- 
ror loci,  nor  any  provision  for  making  diseases. 

How  ail  the  physicians  in  Europe  could  digest  this  absurdity, 
of  yellow  particles,  by  aggregation  and  arrangements  in  sixes 
and  sixes,  becoming  red,  is  not  easy  to  conceive ; nor  is  it  easy 
to  conceive  how  men,  w'hose  education  in  mathematics  and 
algebra  should  have  taught  them  to  think  accurately  and  rea- 
son closely,  could  believe  that  globules  should  break  down  into 
six  particles  each,  and  that  these  particles,  being  themselves 
particles  of  serum,  should  yet  be  distinctly  seen  floating  in  the 
serum.  How  could  these  geometrical  physicians  possibly  be- 
lieve, that  these  particles,  from  large  to  small,  should  descend, 
not  gradually  and  imperceptibly,  but  by  sixes  and  sixes,  one 
after  another  like  steps  of  stairs.^  In  all  his  mathematics,  I do 
not  belive  that  Martin  could  find  any  contrivance  fit  to  help  him 
out  of  these  difficulties.  Martin  observes,  in  his  own  way  of 
geometry,  and  proceeds  to  prove  it  by  most  laborious  schemes, 
“that  just  six  small  sphericles  should  go  to  make  up  one  larger 
globule,  if  you  were  to  choose  the  most  convenient  and  firm- 
est way  of  constructing  it and  then  he  winders  at  Leeuwen- 
hoek finding  it  exactly  so.  But  if  Leeuwenhoek  knew  this  as 
well  as  Dr.  Martin,  I cannot  for  my  heart  think  it  any  wonder 
that  Leeuwenhoek  chose  “the  most  convenient  and  firmest 
way  of  constructing  a red  globule,  viz.  out  of  six  smaller  ones.” 
Seeing  that  he  had  the  affair  entirely  in  his  own  hands,  “what 
a beautiful  haumony  and  rkgulaktiy  do  we  perceive,”  says 
Martin,  “ in  the  mass  of  blood  ! Magnum  certe  opus  oculis  vi- 
deo.” In  plain  truth,  they  desired  but  a little  of  this  harmo- 
ny, a little  consistency  in  their  doctrine,  and  all  was  well. 

But  the  mistakes  concerning  the  formation  or  organizing  of 
this  blood  are  worse  than  these;  for  they  came  from  men  truly 
learned,  and  diligent  in  anatomy,  led  on  by  too  strong  a desire 
of  finding  out  the  uses  of  several  parts  of  the  human  body,  as  of 
the  spleen  and  thymus,  parts  hitherto  unexplained  Mr.  Hew- 
son  supposed  that  the  lymphatic  glands,  which  seem  at  first  to 


0F  THE  BLOOD, 


359 


be  mere  convoluted  vessels,  but  which  being  injected  with 
mercury,  and  cut  into,  are  seen  to  consist  of  numerous  cells, 
form  in  these  cells  the  priniorciia  of  the  red  blood ; for  each 
red  particle  he  supposes  to  consist  of  a central  particle,  which 
is  solid  and  dark-coloured,  surrounded  by  a vesicle  which  is 
transparent  or  white  ; and  this  dark  or  central  part  he  supposes 
is  formed  in  the  lymphatic  cells;  for  he  finds  a sort  of  lound 
particles  in  the  lymph,  and  often  he  finds  the  lymphatics  full 
of  red  blood. 

Next,  be  has  supposed  that  in  the  child  there  is  required  a 
much  greater  supply  of  blood;  for  this  purpose  is  the  thymus 
appointed  ; viz.  to  assist  the  lymphatic  glands  in  organizing 
blood.  This  gland  lies  in  the  upper  part  of  the  chest,  is  great 
in  the  child,  has  vanished  in  the  adult,  but  while  it  exists,  he 
finds  it  full  of  a milky  juice  or  whitish  mucus,  fit  to  make  cen- 
tral particles  for  the  blood ; and  the  lymphatics,  as  he  supposes, 
are  the  excretories  for  this  gland.  He  next  conjectures,  that 
this  work,  begun  thus  by  the  lymphatic  glands,  and  thymus,  is 
perfected  by  the  spleen  ; that  the  lymphatics  make  central  par- 
ticles only,  while  the  vesicular  coverings  are  formed  in  the 
spleen;  so  that  there  only  do  the  particles  become  perfect; 
and  accordingly  of  these  parts  it  is  in  the  spleen  alone  that  the 
red  blood  is  found. 

As  the  central  particles  are  formed  in  the  cells  of  the  lym- 
phatic glands,  the  vesicular  parts  are  formed  in  the  cells  of  the 
spleen,  and  the  lymphatics  unload  these  cells  of  the  particles 
when  completely  formed ; but  there  appears  no  other  proof 
that  they  do  this  office  than  that  there  are  cells  in  the  spleen 
which  may  make  vesicles ; and  that  the  lymphatics  being  tied, 
and  the  spleen  squeezed,  red  gloubles  are  sometimes  found  in 
them. 

Long  poring  over  a wearisome  subject,  and  an  intense  de- 
sire to  finish  that  account  of  the  blood  which  he  had  so  success- 
fully begun,  are  strong  apologies  for  all  these  mistakes.  No 
man  will  venture  to  deny,  that  the  glands  and  lymphatic  ves- 
sels probably  accomplish  some  important  changes  upon  all 
fluids  which  pass  through  them  ; but  that  they  alone  organize 
the  blood,  is  not  to  be  conceived.  Their  containing  round 
white  particles,  argues  nothing;  these  exist  in  the  chjle,  and 
probably  in  that  condition  pass  into  the  blood.  But  if  the  foe- 
tus requires  a great  supply  of  blood,  and  the  thymus  assists  the 
lymphatic  glands,  bow  comes  it,  when  both  lymphatic  glands 
and  thymus  are  working  in  concert  to  prepare  a great  quantity 
of  blood,  that  the  spleen,  which  is  to  finish  all  these  particles, 
and  to  make  vesicles  for  them,  is  not  in  a child  as  big  as  its 
liver  is  ? 


360 


OF  THE  BLOOD. 


That  red  globules  are  found  in  the  lymphatics,  and  most 
especially  in  the  lymphatics  of  the  spleen,  is  a most  ordinary 
occurence,  and  quite  intelligible.  There  are  not  found  any 
where,  not  even  in  the  spleen,  imperfect  globules  advancing  in 
their  organization ; on  the  contrary,  those  which  we  do  find 
are  full  formed  globules  which  have  been  forced  out  of  the 
common  line  of  circulation ; they  are  extravasated,  and  taken 
up  by  the  absorbents  before  death  ; or  they  are  squeezed  into 
them  by  handling  after  death.  If  we  want  to  have  an  example 
of  the  first,  we  have  but  to  inflame  a part  and  tie  up  its  lym- 
phatics, and  then  many  red  particles  are  found  in  them;  the 
second  we  see  every  time  we  either  look  for,  or  prepare  the 
lymphatics  of  the  spleen,  or  of  any  other  soft  viscus;  for  by 
handling  and  squeezing,  the  blood  passes  through  the  small 
breaches  occasioned  by  this  violence  into  the  lymphatics  ; if 
we  allow  the  part  to  spoil,  then  air  is  generated,  and,  by  hand- 
ling it,  air  passes  into  the  lymphatics  in  the  same  way. 

But  the  spleen  is  essential  to  finish  the  work ; it  makes  the 
vesicles,  and  has  cells  for  the  business ; and  yet  this  part, 
which  has  the  most  important  of  all  offices,  viz.  that  of  organi- 
zing the  general  mass  of  blood,  may  be  cut  out  from  dogs 
and  other  animals,  and  they  never  feel  the  loss,  nor  decline  in 
health.  There  is  not  the  smallest  doubt  that  the  spleen  has 
protruded  at  wounds,  and  been  strangled,  and  so  cut  off. 
Every  day  we  find  it  more  or  less  diseased ; sometimes  it  has 
swelled  to  thirty  or  forty  pounds  ; sometimes  it  has  been  re- 
duced to  an  extremely  small  size ; sometimes  it  has  been 
found  like  an  empty  bag. 

In  the  foetus,  as  in  a chick,  for  example,  red  blood  circulates 
in  great  profusion  long  before  its  lymphatics,  spleen,  or  thy- 
mus, can  be  seen  to  exist : whereas,  on  the  contrary,  since  the 
chick  is  insulated,  and  has  no  red  blood  from  the  mother,  the 
spleen  should  have  been  first  coloured,  and  all  the  red  blood 
of  the  system  should  have  emanated  from  the  spleen. 

It  is  but  a poor  evasion  to  say,  in  answer  to  these  objec- 
tions, “ some  other  part  may  perform  this  office  of  the  spleen.” 
What  other  parts  will  perform  the  office  of  the  liver,  if  it  be 
wanting  ’ or  of  the  kidney,  or  of  the  testicle,  or  of  any  other 
gland  ? or  will  the  testicle  secrete  urine,  or  the  kidney  secrete 
bile  ? What  gland,  then,  will  be  able  to  perform  so  peculiar  an 
office  as  this  of  adding  vesicles  or  coverings  to  the  central  parts 
of  the  blood  ? 

After  all  this  long  dream  about  the  vesicles  and  their  cen- 
tral parts,  the  best  physiologists  of  the  present  day  seem  to 
deny  that  they  exist. 

But  one  author  has  finished  this  career  of  useless  specula- 


OF  THE  BLOOD. 


361 


tion,  by  maintaining  that  the  life  is  in  the  blood  : and  thus 
ive  have  seen  this  simple  and  beautiful  subject  of  the  blood 
tortured  through  all  kinds  of  imaginations,  and  running  its 
fiery  ordeal,  first  through  mathematics,  then  through  anatomy 
and  all  its  glands,  then  through  metaphysics ; till  at  last  we 
are  come  to  talk  with  the  most  perfect  ease  and  confidence 
about  the  most  monstrous  of  all  absurdities,  the  life  of  the 
blood. 

“ For  in  the  blood  is  the  life  thereof,”  might  be  a useful 
doctrine  among  the  Jews,  if  it  moderated  their  desire  for 
blood  ; and  if  among  physicians  this  were  to  be  the  tendency 
of  such  a doctrine,  it  were  very  cruel  and  unnatural  to  disturb 
it : but,  in  serious  earnest,  it  introduces  into  modern  physiolo- 
gy nothing  but  a jargon  of  words,  and  perverts  every  idea  that 
the  mind  of  man  can  form  of  parts  which  excite  and  parts 
which  act.  Whimsical  theories  creep  faster  into  physic  than 
useful  facts  ; and  the  business  is  fairly  enough  begun  when 
surgeons,  dissecting  aneurisms  of  the  carotid  arteries,  and 
who  should  be  employed  in  recording  how  and  from  what 
causes  they  have  arisen,  or  how  such  diseases  affect  the  arterial 
coats,  choose  rather  to  inform  us  “ that  this  state  of  the  blood, 
or  rather  of  the  coagulable  lymph,  may  arise  from  some  con- 
nection or  sympathy  it  may  have  with  the  diseased  state  of 
the  artery.”  “ By  lightning,  (says  a celebrated  author,)  death 
is  so  instantaneously  produced  in  the  muscles,  that  they  can- 
not be  affected  by  the  stimulus  of  death.”  Connections,  and 
unknown  sympathies,  and  living  powers  in  fluids,  and  energies, 
and  efforts,  and  intentions,  and  “ sympathetic  congelations  in 
the  blood,”  and  “ immediate  sympathetic  contiguous  harmo- 
nies of  cut  parts,”  and  the  “ diffused  principle  of  life,”  and 
“ the  stimulus  of  death  are  words  which  physiology  would 
gain  by  losing,  and  are  the  very  cant  belonging  to  the  doctrine 
which  I propose  to  refute. 

It  is  not  merely  the  doctrine  of  a living  principle  existing  in 
the  blood  that  is  now  to  be  spoken  of,  but  a doctrine  attri- 
buting the  life  of  the  solids  to  this  living  principle  of  the 
blood  ; so  that  it  may  be  entitled  “ the  new  theory  concerning 
the  blood,  which  is  itself  alive,  which  gives  life  to  all  the  other 
parts,  and  which  in  the  beginning  forms  all  the  parts  out  of 
itself  in  the  mother’s  womb  ; so  that  a foetus  is  merely  a speck 
of  blood,  and  all  the  parts  being  formed  from  that  speck  of 
blood,  the  whole  of  physiology  is  abrogated  henceforward, 
and  totally  annulled,  except  this  theory  itself.  It  is  like  the 
staff  of  Moses  converted  into  a serpent,  which  ate  up  the  ser- 
pents of  all  the  magicians  who  had  thrown  down  the  staff  be- 
fore him  ; for  if  this  theory  were  once  established,  there  would 

VOL.  I.  Z z 


3G2 


OF  THE  BLOOD. 


remain  nothing  to  be  done  in  all  the  animal  body  but  what 
was  done  by  the  blood  ; nothing  to  wont'er  at,  nothing  to 
guess  about,  nothing  to  study,  but  this  vital  and  plastic  power 
of  the  blood. 

The  author  of  this  doctrine  shows  us  two  or  three  specks 
in  an  incubated  egg  ; he  tells  us  that  they  are  dots  of  blood  ; 
he  tells  us  that  this  blood  forms  the  vessels  in  whicli  this  blood 
itself  is  to  move ; it  forms  the  limbs  of  the  chick  which  these 
vessels  are  to  serve  ; the  bones,  muscles,  bowels,  glands,  the 
whole  creature  is  formed  out  of  it;  and  when  the  bird  is  deli- 
vered from  the  egg,  the  living  principle  of  the  blood  still  con- 
tinues to  support  it.  The  blood  heals  its  flesh  or  bones  when 
they  are  broken  ; “ the  blood  moves  in  the  living  solids,  whicli 
it  both  forms  and  supports.” 

It  is  not  easy  to  say  on  which  of  all  his  proofs  Mr.  Hunter 
chiefly  relies  for  establishing  a doctrine  so  important  as  this 
is  ; whether  he  considers  it  as  a perfect  proof  of  the  vitality 
of  the  blood  that  it  coagulates,  or  that  this  coagulum  has 
moreover  the  power  of  becoming  perfectly  alive,  and  of  form- 
ing new  vessels  within  itself;  or  that  blood  seems  to  assist  the 
union  of  contiguous  parts  ; or  that  by  taking  away  its  blood  a 
creature  dies ; or  that  a limb  falls  into  immediate  gangrene 
when  its  vessels  and  its  supply  of  blood  are  cut  off.  But 
chiefly  he  seems  to  rely  on  coagulation  as  a proof  of  the  vi- 
tality of  the  blood  ; for  he  considers  the  coagulation  of  the 
chyle  as  a proof  that  it  also  is  alive  ; and  he  says,  “contrac- 
tion is  the  life  of  the  solids  ; and  if  we  can  find  any  thing  like 
it  (by  which  he  means  coagulation,)  we  shall  call  it  tbe  living 
principle  of  the  blood.” 

But  what  harmony  he  can  find  betwixt  the  occasional,  vo- 
luntary,.regulated,  contractions,  of  the  living  solid  and  this 
sudden,  irretrieveable,  inorganic,  coagulation  of  the  blood,  I 
cannot  conceive.  Does  not  jelly  coagulate  ; and  what  is  it 
but  a part  of  the  blood  Does  not  glue  congeal,  dissolve,  and 
congeal  again,  yet  what  is  it  but  an  animal  jelly?  Does  the 
blood  itself  ever  congeal  till  it  is  out  of  the  body,  orextrava- 
sated  in  aneurismal  sacs.^*  When  it  is  out  of  the  body  it  co- 
agulates ; when  it  coagulates,  It  is  dead  : coagulation  is  so  far 
from  resembling  the  contractions  of  the  living  body,  that  it  is 
the  marked  character  of  dead  animal  matter,  which  you  melt 
and  coagulate  again  and  again.  Shall  we  then  define  life  by 
saying,  coagulation  is  the  mark  of  the  vital  principle  ? If  so, 
we  give  the  mark  of  its  death  as  the  proof  of  its  living  power. 

But  in  his  awkward  attempts,  to  prove  this  point,  the  author 

* From  tbe  most  recent  inquiries  no  jelly  appears  to  be  in  the  blood.  C.  B, 


OF  THE  BLOOD. 


363 


bas  brought  himself  into  great  suspicion,  and  of  course  into 
great  dishonour,  by  two  experiments,  in  which  he  endeavours 
to  show  how  this  vital  power,  like  the  life  of  a perfect  crea- 
ture, is  affected  by  cold  first.  In  page  79,  we  are  informed, 
that  a fresh  egg,  in  consequence  of  being  alive,  resists  the 
cold,  and  is  frozen  with  great  difficulty  ; but  being  once  frozen 
and  thawed  again,  it  loses  its  living  principle  and  its  power  of 
resisting  cold  at  once ; it  freezes  now  at  the  same  tempera- 
ture with  other  animal  matter,  show’ingno  longer  any  power  of 
generating  heat,  or  resisting  cold. 

But  we  are  told,*  that  the  blood  having  a determined  pe- 
riod for  coagulating,  you  may  during  that  time  freeze  the  blood, 
and  it  will  thaw  again,  and  yet  congeal  at  its  proper  time  ; and 
he  tells  us,  that  be  had  very  cleverly  frozen  blood  in  the  very 
time  of  its  flowing  from  the  vein,  then  thawed  the  cake,  and 
still  in  due  time  it  congealed.  Now  since  the  egg  resists  cold 
by  its  living  principle,  why  did  it  die  or  lose  that  living  prin- 
ciple when  converted  into  ice  ? or  rather  since  the  blood  co- 
agulates through  its  living  principle,  and  by  a living  effort,  how 
did  it  preserve  its  living  principle  after  being  frozen.^  This 
proves  surely,  either  that  the  blood’s  coagulation  lias  no  re- 
lation to  any  living  principle,  and  therefore  is  not  affected  by 
the  cold  : or  that  the  egg  has  a living  principle  of  a very  dif- 
ferent kind,  which  is  absolutely  and  totally  extinguished  b)'^ 
cold.  I am  sure  that  had  Mr.  Hunter  seen  these  two  experi- 
ments brought  face  to  face  in  this  manner,  he  would  have  put 
one  of  them  at  least  back  quietly  into  the  portfolio  from 
which  they  both  came.  I have  always  observed,  that  your 
great  tellers  of  experiments  need  to  have  good  memories; 
and  I am  come  to  look  on  a suite  of  experiments  as  coolly  as 
upon  a set  of  neat  plans  and  figures  by  w’hich  the  author 
chooses  to  illustrate  his  hypothesis. 

That  this  coagulurn,  being  once  formed,  has  the  power  of 
becoming  more  perfectly  alive,  and  forming  vessels  within 
itself,  it  is  not  easy  to  conceive.  Nothing  indeed  is  more 
common  than  clots  of  blood,  or  depositions  of  4he  coagula- 
ble  part,  becoming  highly  vascular,  by  vessels  shooting  into 
them  from  surrounding  parts ; but  this  is  of  no  value  in 
Mr.  Hunter's  doctrine ; this  is  not  the  fact  which  he  means  to 
speak  of ; this  is  much  too  natural  and  easy  for  him  : and  that 
his  meaning  may  neither  be  misrepresented  nor  mistaken,  I 
quote  his  words;  “ When  new  vessels  are  formed,  they  are 
not  ahvays  elongations  from  the  original  ones,  but  vessels 
newly  formed,  which  afterwards  open  a communication  with 
the  original.”  That  a clot  of  mere  blood  should  have  in  it 

Page  87. 


364 


OF  THE  BLOOD. 


a living  principle,  and  should  possess  through  that  prin- 
ciple the  power  of  forming  within  itself  arteries  and 
veins,  a new  and  independent  circulation  ; that  it  should 
have  the  privilege  of  knowing  when  it  should  exert  itself  thus, 
is  really  wonderful ; that  it  should  have  some  kind  of  intelli- 
gence, or  consciousness,  by  means  of  which  it  could  under- 
stand when  it  were  within  and  w'hen  without  the  body  ; and 
whether  in  certain  circumstances  it  were  fit  that  such  vessels 
should  be  formed ! That  clots  should  have  been  busied 
forming  vessels  within  them  for  ages,  and  no  body  ever  have 
seen  the  process  going  on  ! That  Mr.  Hunter,  who  has  been 
looking  out  for  vascular  clots  for  thirty  years,  never  should 
have  seen  this  phaenomenon  is  all  very  surprising.  Mr.  Hunter 
falls  into  a deeper  blunder  in  this  business  than  in  the  affair  of 
the  frozen  egg;  he  absolutely  never  saw  a proper  vascular 
clot.  He  informs  us  most  deliberately  in  page  92.,  “ that  he 
thinks  he  has  been  able  to  inject  what  he  suspected  to  be  the 
beginning  of  a vascular  formation  in  a coagulum,  when  it 
could  not  derive  any  vessels  from  the  surrounding  parts.” 
From  whence  then  did  this  clot  derive  its  injection  ^ This 
is  a question  which  detects  at  once  what  Mr.  Hunter  was  do- 
ing, and  puts  this  experiment  pretty  much  upon  a footing 
with  the  frozen  egg. 

To  say  “ that  the  blood,  in  some  circumstances,  unites  liv- 
ing parts  by  a sort  of  contiguous  sympathy  as  certainly  as  the 
yet  recent  branches  of  one  tree  unite  it  with  another,”  is  to 
put  forth  a syllogism,  in  which  both  major  and  minor  proposi- 
tions are  untrue.  First,  it  is  not  true,  that  it  is  the  juices  of 
the  tree  which  unite  the  graff  to  the  stock ; it  is  the  living 
fibres,  and  the  living  vessels  of  both ; and  unless  both  be 
alive,  the  process  must  fail,  living  juices  would  do  no  good. 
Secondly,  though  the  juices  did  so  unite  or  glue  together  the 
branches  of  a tree,  that  were  no  proof  of  the  juices  being 
alive;  but  only  that  good  juices,  whether  alive  or  not  alive, 
were  necessary  to  the  process. 

Any  man  who  affirms  that  in  surgical  operations  it  is  the 
blood,  “ that  by  a contiguous  sympathy  unites  the  parts,” 
should  have  supported  his  assertion  by  this  further  argument, 
that  without  blood  they  will  not  unite.  Prove  to  me  only  that 
fresh  cut  parts  are  not  alive,  and  cannot  naturally  unite  with- 
out the  assistance  of  some  foreign  power,  and  then  I will 
acknowledge  v/illingly  that  they  are  altogether  beholden  to  the 
intermediation  of  the  blood,  with  its  living  principle,  and  sym- 
pathy of  contiguity. 

But  it  is  very  singular  that  any  person,  even  the  least  in- 
■ structed  in  forms  of  reasoning,  should  have  advanced  this  as 


OF  THE  BLOOD. 


365 


any  proof  of  living  principle  in  the  blood,  “ that  mortification 
immediately  follows  where  the  circulation  is  cut  off for  this 
proves  merely,  that  the  blood  is  one  of  many  stimuli,  by  which 
the  system  is  supported,  insomuch,  that  each  limb  is  affected 
just  as  the  whole  body  would  be ; and  whether  you  stop  the 
blood,  which  is  one  stimulus,  or  take  away  its  heat,  which  is 
the  stimulus  next  in  power  to  the  blood,  the  limb  will  equally 
die. 

To  say  that  the  life  is  in  the  blood,  because  the  blood  be- 
ing taken  away  the  limb  dies,  or  because  an  animal  may  be 
bled  till  it  dies ; what  is  this  but  to  jumble  all  distinction  of 
cause  and  effect  The  water,  no  doubt,  is  the  life  of  the  mill, 
and  the  plough-horse  is  the  very  life  of  the  plough ; for  the 
mill  and  the  plough  are  dead  the  moment  that  the  horse  is 
gone  or  the  water  fails. 

Lastly,  we  are  told  “ that  it  is  by  the  contiguous  sympathy 
of  the  blood  and  body  both  being  alive,  “ that  they  both  work 
upon  each  other  mutually : but  it  is  not  very  strange  for  any 
physiologist  to  forget,  that  the  blood  is  at  least  in  part  a foreign 
body,  that  it  must  be  continually  impregnated  with  air,  that  it 
is  neither  its  original  constitution,  nor  these  presumed  sympa- 
thies that  make  it  vital  blood,  that  it  becomes  vital  blood  only 
by  exposure  to  air,  and  that  if  this  foreign  principle  be  not 
continually  added,  the  solids  are  not  wrought  upon  by  the 
blood  ? 

The  natural  difficulties  of  this  doctrine  are  very  great ; for 
it  seems  to  be  against  all  the  laws  of  nature  that  any  fiuid  should 
be  endowed  with  life.  A fluid  is  a body  whose  particles  often 
are  not  Homogeneous,  have  no  stable  connection  with  each 
other,  change  their  place  by  motion,  change  their  nature  by 
chemical  attractions  and  new  arrangements ; a body  which  can 
have  no  perfect  character,  no  permanent  nature,  no  living 
powers  connected  with  it.  But  the  definition  of  a solid  is  the 
reverse  of  this  : a solid  among  every  kind  of  metals,  earths,  or 
fossils,  is  recognized  by  its  peculiar  form,  and  arrangement  of 
parts:  and  in  the  animal  body,  the  arrangement  of  particles 
gives  the  permanent  unchanging  character  of  each  part ; and 
in  the  muscles,  for  example,  or  in  the  nerves,  where  feeling 
and  irritability  chiefly  reside,  the  form  and  mechanism  of  the 
solid  is  in  each  most  peculiar,  and  is  always  the  same. 

What  is  this  blood,  that  it  should  begin  life  and  support  it, 
and  distribute  it  through  all  the  system  Is  it  not  a fluid  which 
varies  every  hour,  now  richer,  now  poorer,  now  loaded  with 
salts,  now  drowned  in  serum,  now  much,  now  sparingly  sup- 
plied with  air,  now  darker  coloured,  now  red,  now  fully  sup- 

* There  is  no  proof  tiiat  oxygen  is  absorbed  in  respiration,  but  only  carbon  removed. 


366 


OP  THE  BLOOD. 


plied  with  chyle,  and  row  starvedof  its  usual  supply?  Is  it  not 
lost  in  astonishing  quantities  in  hirmorrhages,  and  drawn  very 
freely  from  our  veins  upon  the  slightest  disease  ? That  such 
qualities  are  consistent  with,  life  in  the  blood,  is  what  I cannot 
believe.  But  I can  most  easily  imagine  how  the  system, 
having  by  successive  operations  converted  the  food  into  chyle, 
the  chyle  into  blood,  and  fashioned  the  nutritious  part  of  the 
blood  into  various  solids;  these  new  solids  may  partake  of  the 
vitality  of  all  the  parts  to  which  they  are  applied,  and  to 
which  they  have  been  assimilated  by  so  peculiar  and  so  slow 
a process. 

The  question  is  plainly  this  : Shall  we  follow  the  general 
laws  of  the  system,  such  as  physiology  acknowledges  ? or 
shall  we  admit  an  absurd  novelty  without  proof?  Shall  we 
allow  of  the  simple  accident  of  coagulation  (an  accident  com- 
mon to  dead  fluids)  as  a proof  of  life  ? or  shall  we  forget  those 
stupendous  proofs  of  the  irritability  residing  in  the  heart, 
muscles,  and  other  forms  of  our  living  solids,  and  which  is  the 
source  of  all  the  various  actions  of  the  body  ? Shall  we  for- 
get that  polypi,  worms,  insects,  the  bloodless  parts  of  fishes, 
the  uncoloured  parts  of  the  human  body,  even  plants  almost 
inanimate,  all  partake  of  life,  without  having  red  blood  in 
their  system,  or  having  it  restricted  to  the  central  parts  P All 
these  have  life  and  vitality,  but  where  is  their  blood  ? In 
short  the  question  plainly  resolves  itself  into  this,  Shall  we 
have  two  living  parts,  fluid  and  solid  ; two  agents  acting  on 
each  other  ^ or  shall  we  follow  the  common  law  of  the  oeco- 
nomy,  call  the  one  an  exciting  power,  while  the  other  receives 
that  excitement,  being  alive  only  that  it  may  feel  and  act  ac- 
cording to  the  degree  in  which  it  is  moved  ? Shall  we  have 
the  blood  communicating  life  to  all  the  body;  or  the  body 
only  alive,  and  the  blood,  like  various  other  excitements,  act- 
ing upon  it  with  those  powers  w’hich  it  is  continually  acquir- 
ing, without  acquiring  along  with  them  any  share  of  life  ? 

But  Mr.  Hunter,  ill  contented  with  his  doctrine  himself,  he 
even  who  began  with  giving  to  the  blood  a vital  principle,  and 
calling  it  the  former  of  new  parts,  and  the  substance  whence 
the  living  solid  derives  its  life,  hatches  a new  doctrine  out 
of  the  confusion  of  the  first;  takes  from  the  blood  all  those 
high  privileges  in  the  system  which  he  had  so  freely  bestowed 
upon  it,  and  gives  them  in  full  perpetuity  to  a new  principle, 
a principium  vit:c  dilfusae,  which  he  announces  thus  : 

“ I would  consider  that  something  similar  to  the  substance 
of  the  brain  is  diffused  through  the  body,  and  even  contained 
in  the  blood  ; and  between  this  (viz.  the  matter  diffused  in  the 
blood)  and  the  brain  the  coraimmication  is  kept  up  by  nerves." 


OP  THE  BLOOD. 


367 


This  matter  he  does  not  like  to  define,  but  be  must  name  it; 
and  having  observed,  as  others  have  done,  that  a mouthful  of 
nonsense  sounds  infinitely  better  in  Latin  than  in  our  mother 
tongue,  he  calls  it  the  “ Materia  vitas  diffusa.” — Concerning 
this  diffused  principle  of  life,  he  tells  us,  that  every  part  of  an 
animal  has  its  due  proportion  ; it  unites  all  the  body  into  one  ; 
‘‘  it  is  as  it  were  diffused  through  the  whole  solids  and  fluids, 
making  a necessary  constituent  part  of  them,  and  forming  with 
them  a perfect  whole.” — The  terms  in  which  this  doctrine  is 
proposed  are  hardly  more  intelligible  than  those  in  which  he 
argues  about  the  life  of  the  blood  ; the  matter  itself  resembling 
the  substance  of  the  brain,  is' supposed!  the  manner  of  its 
union  with  the  blood  is  supposed  ! its  connection  at  once  with 
the  fluids,  and  with  the  living  solids,  is  supposed  ! the  sort  of 
a manner,  in  which  this  matter  harmonizes  the  whole,  is  sup- 
posed ! and  now  the  coagulation,  and  life  of  the  blood, 
is  no  longer  an  effort  of  the  life  of  the  blood,  but  of  the  ma- 
teria vit£B  diffusa ; and  the  blood  does  not  form  the  solids,  the 
blood  no  longer  communicates  life  to  the  solids,  but  the  blood 
and  the  solids  are  both  at  once  animated  by  this  DiFeuseo 

PRINCIPLE  OF  LIFE. 

No  one  need  triumph  over  a doctrine  which  thus  falls  by 
its  own  weight ; but  this  must  not  be  forgotten,  that  the  doc- 
trine of  the  life  of  the  blood  leads  to  a mean,  contracted,  nar- 
I’ow  view,  not  merely  of  this  but  of  higher  subjects. 

Plants  have  active  and  irritable  fibres  ; by  the  most  curious 
actions  they  drink  in  w'ater ; water  alone  they  can  convert,  by 
the  most  simple  mechanism,  into  most  delicate  perfumes,  into 
delicious  fruits,  or  into  terrible  poisons.  “ There  stands,” 
says  Blumenbach,  “ a hyacinth  before  me ; generations  of 
these  flowers,  of  which  this  is  the  last,  have  grown  there  suc- 
cessively, touching  the  surface  merely  of  a little  water;”  but 
shall  Mr.  Hunter  persuade  me  that  this  water  is  alive  ? “ vel 
hyacinthi  me  monent.”* 

I think  I may  safely  conclude,  that  these  theorists  have  done 
the  science  no  good  ; themselves  no  honour ; and  us  no  kind 
of  benefit,  unless  it  be  an  advantage  to  knovv  that  by  none  of 
these  ways  can  we  arrive  at  a knowledge  of  the  blood.f 

QUALITIES  OF  THE  BLOOD. 

Blood  is  a fluid  of  a rich  and  beautiful  colour ; it  is  ver- 
milion-coloured in  the  arteries,  strong  purple  in  the  veins,  and 

* Page  27. 

t Notwithstanding  the  force  of  this  criticism,  which  is  too  valuable  not  to  be  left  on  re- 
cord, the  doctrine  of  tlie  life  of  tho  blood  is  in  my  mrnd  the  best  established  doctrrae  ®f 
'Tiodem  physiology',  C.  E. 


368 


OF  THE  BLOOD. 


black,  or  almost  so,  at  the  right  side  of  the  heart ; it  feels 
thick  and  unctuous  betwixt  the  fingers,  is  of  a slightly  saline 
taste,  is  various  in  various  parts  of  the  body,  in  tbe  heart  or 
at  tile  centre  of  the  circulation  different  from  what  it  is  in  the 
glands,  excretories,  and  all  the  extremeties  of  the  body ; dif- 
ferent in  the  liver,  among  the  intestines,  in  the  cheeks  and  lips, 
in  the  reservoir  or  sinuses  of  the  head  and  womb.  In  various 
individuals,  but  much  more  in  different  animals,  it  varies  with 
their  functions  and  manner  of  life  ; it  is  more  or  less  perfect 
in  animals,  in  birds,  in  fishes,  in  insects  ; it  is  thick  or  thin  ; 
has  gross  particles  or  small ; is  red  or  pale  ; hot  or  cold  ; ac- 
cording to  the  creature’s  life  : and  from  this  last  variety,  viz. 
of  the  manner  of  life,  comes  our  division  of  animals  into  those 
of  hot  and  cold  blood. 

It  is  by  the  most  simple  and  natural  methods  that  we  exa- 
mine the  blood;  since  almost  spontaneously  it  resolves  itself 
into  the  crassamentum,  the  serum,  and  the  red  globules, 
suspended  in  the  crassamentum,  and  forming  a part  of  it.  In 
a cup  of  blood,  the  crassamentum,  or  clot,  the  hepar  sangui- 
neum,  as  it  was  called  long  ago,  floats  in  the  serum  ; the  red. 
globules  are  engaged  in  this  clot,  and  give  it  colour  ; the  serum 
may  be  poured  off,  the  coagulum  may  be  washed  till  it  is  freed 
of  the  red  parts  of  the  blood  ; and  then  the  red  particles  are 
found  in  the  water  with  which  the  coagulum  was  washed,  and 
the  coagulum  remains  upon  the  strainer,  little  reduced  in  size, 
pure  and  white,  the  fibrine  or  gluten.  Or  we  may  separate 
this  part  by  a method  which  Ruysch  first  taught  us  ; we  may, 
while  the  blood  is  congealing,  stir  it  with  a bunch  of  rods, 
when  the  pure  and  colourless  fibrine  gathers  upon  the  rods, 
and  the  serum,  with  the  red  particles  suspended  in  it,  remains 
behind. 


OF  THE  RED  GLOBULES. 

The  red  globules,  as  we  have  observed,  are  not  universal ; 
yet  in  all  creatures,  even  in  colourless  insects,  there  seem  to 
be  formal  particles  in  the  blood  ; in  white  Insects  they  are 
white,  in  green  insects  they  are  green,  in  most  insects  they  are 
transparent. 

The  red  globules  of  the  human  blood  are  easily  seen ; they 
are  best  examined  with  a simple  lens,  the  globules  being  dilu- 
ted in  serum  and  laid  upon  an  inclined  plane,  not  in  water, 
which  dissolves  them  quickly,  but  in  serum  which  has  tbe  pro- 
perty of  preserving  their  globular  form. — The  size  of  the  par- 
ticles of  the  blood  varies  in  various  creatures ; in  the  foetus, 


OF  THE  BLOOD. 


369 


tliey  are  bigger  than  in  a grown  animal ; and  though  Leeuwen- 
hoek thought  it  essential  to  his  doctrine,  to  say,  that  they  were 
alike  in  all  creatures,  we  know  beyond  a doubt  that  there  are 
in  respect  to  the  size  of  the  animals  the  strangest  reverses. 
The  Skate  has  red  globules  much  larger,  and  the  Ox  has  glo- 
bules much  smaller,  than  those  of  a Man.  Fish  have  large 
globules.  Serpents  smaller  ones,  and  Man  smaller  still.  In 
Man  the  diameter  of  each  globule  is  much  less  than  the  three 
thousandth  part  of  an  inch. 

There  is  in  the  effect  of  lenses,  or  in  the  nature  of  these 
globules,  some  strange  refraction,  by  which  there  seems  a 
darkness  in  the  centre  of  each  globule,  and  thence  a deception 
which  has  been  universal;  so  that  no  single  description  has 
tallied  with  that  which  went  before.  Leeuwenhoek  believed, 
that  he  saw  them  consisting  each  of  six  well  compacted  smaller 
globules  : Hewson  believed  that  they  were  bladders,  which  had 
within  them  soine  central  body,  loose  and  moveable ; that 
often  the  central  part  might  be  seen  rolling  in  its  bag  ; and 
that  sometimes  the  bladder  was  shrunk  and  shrivelled  around 
the  central  body,  and  could,  by  putting  a drop  of  water  upon 
it,  be  plumped  up  again.  The  Abbe  Torre  examined  them 
with  simple  lenses  too ; but  they  magnified  so  highly,  that 
from  this  cause  all  his  noisy  mistake  has  arisen ; for  he  used 
not  ground  lenses  but  small  sphericles  of  glass  formed  by  drop- 
ping melted  glass  into  water  ; they  magnified  so  much,  that  to 
him  the  central  spot  appeared  much  darker ; he  said  that  these 
were  not  globules,  but  rings.  He  sent  his  sphericles  of  glass 
and  his  observations  from  Italy,  his  own  country,  to  our  Royal 
Society  ; and  for  a long  while,  though  nobody  could  see  them, 
still  the  public  were  annoyed  by  Abbe  Torre’s  rings.  Fal- 
coner, with  all  the  zeal  of  a friend,  published  Hewson’s  dis- 
coveries after  he  was  dead  ; lamenting,  as  we  all  must  do,  the 
loss  of  a promising  young  man.  Falconer  thought  he  saw 
these  globules,  not  as  spheres,  but  as  flattened  spheres ; he 
thought  he  saw  them  often  as  they  rolled  down  the  inclined 
plane  upon  which  he  placed  them,  turning  their  edges,  their 
sides,  their  faces,  towards  the  eye ; he  even  compared  their 
flatness  with  that  of  a coin.  Many  authors  have  conjectured 
that  these  globules  are  compressed  w'hen  they  come  into  nar- 
row passages,  and  expand  again  when  they  ^t  into  wider  arte- 
ries. This  Reichell  says  he  has  seen,  and  Blumenbach  be- 
lieves ; but  Blumenbach,  less  easy  of  belief  with  regard  to  all 
these  strange  forms  ascribed  to  the  particles  of  the  blood, 
pronounces  his  dissent  in  plain  terms.  “ They  appear,”  says 
he,  “ to  my  eye  no  other  than  simple  globules  apparently  of 

VOL.  I.  A a a 


370 


OF  THE  BLOOD. 


mucus  : that  lenticular  or  oval  form  which  authors  speak  of,  I 
have  not  seen.” 

The  following  are  their  chief  properties  with  regard  to  the 
rest  of  the  blood.  When  blood  stands,  they  fall  to  the  bot- 
tom, because  they  are  heavier  than  the  other  parts  of  the 
blood  ; and  although  the  fibrine  or  gluten  entangles  them  while 
it  is  forming,  still  it  is  to  be  noticed  that  the  cake  is  always 
redder  at  the  bottom  ; and  when  by  weakness  or  disease  this 
coagulation  is  very  slow,  some  globules  escape  the  grasp  of 
the  coagulum,  and  the  serum  is  tinged  with  red,  and  the  cake, 
though  coloured  at  the  bottom,  is  white  at  the  top,  or  has  the 
huffy  coat.  Their  form  they  preserve  only  while  in  the  blood, 
and  seem  to  be  supported  more  by  the  qualities  of  the  serum 
than  by  their  own  properties ; for  if  mixed  with  water,  they 
mix  easily,  and  totally  dissolve  ; the  water  is  red,  but  the  glo- 
bules are  gone  ; when  we  mean  to  preserve  their  forms  for  ex- 
periment, we  must  keep  them  in  serum,  or  must  make  an  arti- 
ficial serum  by  impregnating  water  with  salts.  Their  quantity, 
in  regard  to  the  whole  mass,  varies  so,  that  the  appearance  of 
the  blood  is  a real  index  of  health  or  disease  : in  disease  and 
weakness,  the  blood  is  poor  and  colourless ; in  health  and 
strength,  it  is  rich  and  florid ; by  labour,  red  particles  may  be 
accumulated  in  a wonderful  degree  ; in  hard  working  men  they 
abound ; they  may  be  accumulated  by  exercise  into  particular 
parts,  as  in  the  wings  of  Moorfowl  or  Pidgeons,  and  in  the  legs 
of  common  Hens.  In  short,  the  red  globules  are  numerous 
in  health  ; in  large  and  strong  creatures ; and  in  the  centre  of 
the  system,  where  they  often  circulate,  when  (as  in  fishes)  all 
the  flesh  is  colourless ; in  such  a system,  particular  glands 
only,  or  viscera,  as  the  liver,  stomach,  or  spleen,  are  coloured 
with  blood,  and  but  a small  proportion  circulates  in  the  great 
vessels  round  the  heart. 

The  redness  of  these  particles  is  a peculiarity  for  which  we 
know  no  meaning  nor  cause.  The  greatest  physiologists  have 
ascribed  it  to  the  iron  of  the  blood  ; but  when  we  reflect  how 
many  various  colours  iron  gives  in  its  various  states  ; when  we 
reflect,  that  the  unknown  cause  which  gives  colour  to  the  iron 
may  give  colour  to  the  blood ; when  we  reflect,  that  of  this 
crocus  of  iron  we  can  hardly  procure  one  poor  grain  from  four 
hundred  grains  of  these  red  particles  of  the  blood ; we 
cannot  but  be  conscious  that  this  peculiarity  is  not  yet  ex- 
plained.* 

According  to  BerzeliuJ,  about  one-fourth  of  the  dry  colouring  matter  is  oxj’deofiroB; 


OF  THE  BLOOD. 


sn 


COAGULABLE  LYMPH. 

The  coagulable  part,  the  cake  which  is  left  when  we  wash 
away  the  red  globules,  that  which  has  been  called  the  gluten, 
and  now  by  chemists  the  fibrine,  is  by  far  the  most  important 
part  of  the  blood,  the  most  universally  diffused  in  the  animal 
system,  the  most  necessary  for  the  supply  and  growth  of  parts. 
It  forms  all  the  solids,  and  in  its  properties  resembles  them 
most  curiously;  for  this  cake,  when  washed,  is  white,  insipid, 
extremely  tenacious,  and  very  fibrous;  can  be  drawn  out 
greatly ; and  it  is  the  coagulation  of  this  part  that  makes  the 
long  fibrous  strings  which  we  find  in  the  tub  when  bleeding  a 
patient  in  the  foot  in  very  hot  water.  Being  slightly  dried,  it 
shrinks  into  a substance  like  parchment ; being  hardened  by 
heat,  it  becomes  like  a piece  of  horn  or  bone  : when  burnt,  it 
shrinks  and  crackles,  with  a very  fetid  smell,  like  the  burning 
of  feathers,  wool,  flesh,  or  any  other  animal  substance ; 
by  which  we  know  it  to  be  the  part  of  the  blood  which  is  the 
most  perfectly  animalized,  and  the  most  ready  to  be  assimi- 
lated with  the  living  solids.  When  distilled,  it  gives  ammo- 
niacal  salt  and  alkaline  water,  and  a very  thick  heavy  fetid  oil, 
and  much  mephitis,  which  are  the  marks  of  the  most  perfect 
animal  nature;  and  after  burning  it,  the  residuum  is  a 
phosphate  of  lime,  or,  in  other  words,  the  earth  of  bones. 

Its  peculiar  properties,  as  it  appears  in  the  blood,  are  few ; 
its  relation  to  the  body  is  very  surprising. 

What  passes  within  the  animal  body,  or  how^  this  gluten  is 
directly  applied,  we  never  can  know ; but  we  see  how  the 
greater  part  of  the  body  is  composed  of  gluten,  and  no 
analysis  of  any  single  part  has  ever  disappointed  us.  A mus- 
cle being  squeezed,  and  thoroughly  cleansed  of  blood,  washed 
in  spirits  of  wine,  and  again  cleaned,  is  seen  plainly  to  be  but 
a peculiar  form  of  coagulable  lymph.  A bone  being  infused 
in  any  mineral  acid,  or  in  vinegar,  its  earthy  parts  are  dis- 
solved even  to  its  centre ; it  becomes  soft  and  flexible,  still 
retains  the  form  of  a bone ; but  what  remains  consists  princi- 
pally of  coagulable  lymph.  And  though  Fourcroy  is  certainly 
right  in  saying  that  coagulable  lymph  is  that  part  upon  which 
nature  fixes  irritability,  or  the  contractile  power,  he  should 
have  added,  “ but  this  gluten  is  moreover  in  the  animal  body 
the  basis  of  every  part  which  possesses  life  ;”  it  constitutes, 
in  truth,  no  less  than  nine-tenths  of  the  solids  of  the  whole 
body.  The  membranes,  ligaments,  tendons,  periosteums, 
and  all  the  white  parts  of  the  animal  body,  consist  chiefly  of 
this.  It  is  this  fibrous  part,  then,  which  is  secreted  by  the 


372 


OF  THE  BLOOD. 


vessels  for  repairing  all  the  wastes,  and  all  the  accidents  of  the 
body  ; when  a muscle  is  wasted  by  violent  action,  or  by  fevers, 
or  by  long  confinement  is  absorbed,  gluten  is  secreted  to  fill  it 
up  ; when  a bone  is  broken,  much  of  this  jelly  is  deposited  in 
a bed  for  vessels  to  stretch  into,  and  a new  bone  is  quickly 
formed  ; when  soft  parts  are  cut,  gluten  is  poured  out  betwixt 
them  ; when  viscera  are  inflamed,  pure  gluten,  white,  and 
membranaceous-like,  is  poured  out  betwixt  them ; when  the 
uterus  is  to  be  prepared  for  receiving  the  impregnated  ovum, 
gluten  is  poured  out  into  the  womb ; and  in  all  these  cases  it  is 
the  foundation  of  a union  with  the  surrounding  parts.  In  short, 
this  gluten  forms,  nourishes,  supports,  restores  the  parts  of  the 
animal  body ; but  far  from  considering  it  either  simply,  or 
along  with  the  red  globules,  as  containing  the  principle  of  life, 
I find  it  as  perfect  in  dead  vegetables  as  in  living  animals  ; and 
view  it  only  as  that  particular  form  of  matter  which  nature 
has  wisely  appointed  for  our  chief  nourishment  and  support. 


THE  SERUM. 

The  serum  is  the  thinnest  and  most  fluid  of  the  parts  of  the 
blood,  into  which  it  spontaneously  separates.  And  it  contains 
those  substances  which  one  is  almost  tempted  to  call  extrane- 
ous : this  must  be  kept  in  view  when  its  properties  are  to  be 
told,  for  though  it  so  exactly  resembles  the  white  of  an  egg, 
that  some  have,  in  comparing  the  two,  written  whole  pam- 
phlets on  the  subject,  and  named  it  the  Albuminous  Fluid,  al- 
though it  coagulates  like  gluten,  although  it  putrefies  like 
flesh,  although  it  gives  out,  upon  distillation,  ammonia  and  a 
black  and  fetid  oil ; yet  it  is  most  natural  that,  along  with  these, 
it  should  contain  also  some  foreign  bodies,  as  a saccharine  or 
extractive  matter,  belonging  to  vegetables,  and  some  propor- 
tion of  the  oxalic,  malic,  or  other  vegetable  acids.* 

Serum  is  a fluid  like  whey,  of  a yellowish,  or  rather  greenish 
colour,  of  an  unctuous  or  slippery  feeling  among  the  fingers; 
it  is  slightly  saline,  and  contains  soda,  sulphur,  and  phosphate 
of  iron.  It  contains  soda  completely  formed,  by  which  it  turns 
vegetable  reds  to  green  ; it  coagulates  with  a heat  much  lower 
than  that  which  makes  it  boil;  being  dropped  into  hot  water  it 
coagulates  as  it  falls ; by  150  degrees  of  heat,  it  coagulates 
into  an  albumen  like  the  white  of  an  egg. 

But  by  this  influence  of  heat  the  whole  does  not  coagulate, 
but  only  the  albumen,  a substance  like  the  white  of  an  egg; 

* The  lactic  acid  is  the  only  free  acid  hitlierto  found  in  it.  C.  B. 


OF  THE  BLOOD. 


375 


what  remains  fluid  is  the  serosity.  On  cooling,  the  serosity 
coagulates  like  size  or  jelly.  This  coagulation  arises  from  the 
gelatin  dissolved  in  the  water  ; and  this  gelatin  may  be  preci- 
pitated by  various  re-agents,  but  especially  by  tanin,  and  by 
alcohol.  After  the  separation  of  the  gelatin,  thei’e  remains 
only  the  salts  in  watery  solution ; these  are  muriate  of  soda, 
phosphate  of  soda,  and  phosphate  of  lime. 

This  analysis  of  the  blood  contains  the  analysis  of  almost  all 
the  humours  or  secretions  of  the  body.  Observe  how  nearly 
the  urine  resembles  the  serum  ; indeed  the  urine,  like  the 
serum,  preserves  the  peculiar  form  of  the  red  globules,  and 
sweat  is  but  a serum  loaded  wuth  salts ; observe  how  little 
saliva  differs  from  the  serum  ; observe  how  perfectly  the  serum 
resembles  milk,  since  mixing  serum  Avith  water  produces  a 
milky  fluid,  that  is,  a fluid  wdiich  gathers  cream  on  the  top, 
and  coagulates  with  acids  and  heat.  The  water  of  dropsies 
is  purely  serum ; the  mucus  of  hollow  passages  is  little  else 
than  inspissated  serum  ; the  bile  itself  is  said  to  be  imitated 
by  keeping  putrid  blood.*  In  short  it  is  obvious  that  on  the 
coagulable  lymph  depend  all  the  internal  secretions,  (?’.  e.)  for 
supplying  the  waste  of  the  system,  for  enabling  it  to  grow, 
for  repairing  bruised  or  cut  flesh,  or  broken  bones  ; that  on 
the  serum  which  dilutes  the  blood,  and  contains  all  such  foreign 
bodies  as  might  be  injurious  to  the  system,  all  the  excretions, 
as  urine,  sweat,  saliva,  tears,  &c.  &c.  depend. 

I have  said,  “ that  the  blood  is  a fluid  of  a rich  and  beauti- 
ful colour ; vermilion-coloured  in  the  arteries,  strong  purple 
in  the  veins,  and  black,  or  almost  so,  at  the  right  side  of  the 
heart.”  When  we  open  the  thorax  of  a living  Dog,  the  lungs 
collapse,  the  heart  soon  ceases  to  play,  the  Dog  languishes,  ex- 
pires, is  revived  again  when  we  blow  up  its  lungs : — then  begins 
again  the  motion  of  the  heart,  the  black  blood  of  the  right 
auricle  is  driven  into  the  lungs ; the  blood  goes  round  to  the 
left  side  of  the  heart  of  a florid  red  ; and  this  purple  blood  of 
the  veins,  the  vermilion  blood  of  the  arteries,  the  change  hap- 
pening so  plainly  from  access  of  air,  is  a phenomenon  of  the 
most  interesting  nature,  and  binds  us  to  look  into  the  doctrines 
of  chemistry  for  the  solution  of  a phenomenon  to  which  there 
is  in  all  the  animal  economy  nothing  equal. 

It  is  the  study  of  air  and  aerial  fluids  that  has  brought  to 
light  all  the  beautiful  discoveries  of  which  modern  chemistrv 
can  boast.  The  simplicity  of  the  facts  in  chemistry,  the  cor- 
rectness of  the  reasoning,  the  grandeur  which  now  the  whole 
science  assumes,  is  very  pleasing;  and  makes  us  not  w'ithout 

* With  the  exception  of  the  water  of  dropsies,  all  the  fluids  mentioned  here  have  been 
found  very  cflfferentfrom  semm. 


374 


OF  THE  BLOOD. 


hope,  that  by  this  science,  all  others,  and  ours  in  an  especial 
manner,  may  be  improved ; for  the  action  of  vessels  will  do 
much  in  forming  and  changing  our  fluids:  all  the  rest  is 
chemistry  alone. 

The  older  chemists  were  coarse  in  their  methods,  bold  in 
their  conjectures,  in  theory  easily  satisfied  with  any  thing 
which  others  would  receive.  They  condescended  to  repeat 
incessantly  the  same  unvarying  process  over  each  article  of 
the  materia  medica  ; and  among  hundreds  of  medicinal  plants 
which  they  had  thus  analysed,  they  could  find  no  variety  of 
principles,  nor  any  other  variety  of  parts  and  names  than  those 
of  i.hlegm,  and  oil,  and  alkali,  and  acid,  and  sulphur,  and 
coal.  By  tliis  they  disburthened  their  consciences  of  all  they 
knew,  pleased  their  scholars,  and  set  the  physicians  to  work, 
forming  magnificent  theories  of  salts,  sulphurs,  and  oils ; for 
such  has  ever  been  the  connection  of  chemistry  with  physi- 
ology, that,  good  or  bad,  they  have  still  gone  hand  in  hand. 

The  older  chemists  thought  that  they  had  arrived  at  the 
pure  elements,  while  they  were  working  grossly  among  the 
grosser  parts  of  b dies.  They  could  know  nothing  of  the 
aerial  forms  of  bodies,  for  they  allowed  these  parts  to  escape. 
When  their  subjects  by  extreme  torce  of  heat,  rose  upwards 
in  the  form  of  air,  no  further  investigation  was  attempted ; it 
was  supposed  that  the  subject  of  their  operation  was  consumed, 
annihilated,  wasted  into  air,  and  quite  gone.  When  they  thus 
stopped  at  airs,  they  stopped  where  only  their  analysis  became 
interesting  or  simple ; stopping  where  they  stopped,  among 
their  oils  and  sulpliurs,  they  made  their  science  a mere  I’hap- 
sody  of  woi  ds.  Philosophy  they  considered  so  little,  as  not 
to  know  that  the  lightest  air  is  really  a heavy  body,  and  that 
with  weight  and  substance  other  properties  must  be  presumed. 

Modern  chemistry  begins  by  assuring  us,  that  these  airs  are 
often  the  densest  bodies  in  the  rarest  forms;  that  airs  are  as 
material,  as  manifest  to  the  senses,  as  fairly  subject  to  our  ope- 
rations, as  the  dense  bodies  from  which  they  are  produced : 
that  it  is  heat  alone  (a  substance  which  irresistibly  forces  its 
way  into  all  bodies)  that  converts  any  substance  into  the  aerial 
form : that  some  bodies  require  for  their  fluidity  merely  the 
heat  of  the  atmosphere,  and  so  cannot  appear  on  this  planet  in 
any  solid  form : that  others  require  some  new  principle  to  be 
added,  in  order  to  give  them  the  gaceous  or  aerial  form  : that 
others  require  very  intense  heat  to  force  them  into  this  state; 
but  that  all  aerial  fluids  arise,  or  must  be  presumed  to  arise, 
from  some  solid  body  or  basis,  which  solid  basis  is  dilated  by 
heat  into  an  air.  The  solid  basis  of  some  airs  can  be  made  appa- 
rent, as  of  fixed  air,  which  proceeds  from  charcoal ; others,  as 


OP  THE  BLOOD. 


375 


pure  air,  or  azotic  air,  (the  great  constituents  of  our  atmos- 
phere,) cannot  be  produced  to  view  in  any  solid  form.  But 
those  airs  which  cannot  be  exhibited  in  any  solid  form,  can  yet 
be  so  combined  with  other  bodies  as  to  increase  their  weight, 
and  give  them  qualities  of  a very  peculiar  nature ; and  these 
airs  can  be  alternately  combined  with  a body  and  abstracted 
again,  adding  or  abstracting  from  its  weight  and  chemical  pro- 
perties, not  only  in  a perceptible,  but  in  a wonderful  degree ; 
so  that  these  abstractions  and  combinations  constitute  some  of 
the  most  general  and  important  facts.  When  the  old  chemists, 
then,  neglected  to  examine  these  airs,  they  refrained  from  ex- 
amining the  last  elements  of  bodies  at  the  very  moment  in 
which  they  came  within  their  power. 

That  these  must  be  the  most  material  and  important  facts 
in  all  the  science,  it  is  easy  to  explain  ; for  chemistry,  ever 
since  it  has  been  a science,  has  rested  upon  one  single  point. 
There  are  certain  great  operations  in  chemistry  which  we  per- 
ceive to  have  the  strictest  analogy  with  each  other,  or  rather 
to  be  the  same  ; the  operations  are,  the  combustion  of  inflam- 
mable bodies,  the  respiration  of  animals,  the  calcination  of  me- 
tals ; and  whatever  theory  explains  one  explainsthe  whole.  The 
older  chemists  observed,  that  when  they  burnt  an  inflamma- 
ble body,  the  surrounding  air  was  contaminated,  the  substance 
itself  was  annihilated,  nothing  remained  of  its  former  existence 
but  the  foul  air;  and  they  supposed  that  this  inflammable  body 
consisted  of  a pure  inflammable  principle,  which  was  the  sub- 
stance which  spoiled  the  air,  lessening  its  bulk,  and  making  it 
unfit  for  supporting  any  longer  either  combustion  or  animal 
life.  When  an  animal  breathed  in  confined  air,  they  found  the 
phenomenon  still  the  same;  the  animal  contaminated  the  air, 
and  expired  itself ; left  the  air  unfit  for  burning  or  breathing, 
loaded,  as  they  supposed,  with  the  inflammable  principle. 
When  they  calcined  a metal,  (which  is  done  merely  by  heat- 
ing the  metal  and  exposing  it  to  air,)  they  found,  as  in  these 
other  operations,  the  air  contaminated,  the  metal  losing  its  me- 
tallic lusti’e,  ductility,  and  all  the  marks  of  a metal, — acquir- 
ing (in  certain  examples)  new  qualities,  like  those  of  some  mi- 
neral acid,  and  becoming  of  course  a most  caustic  drug;  but 
above  all,  they  uniformly  observed  the  metal  to  increase  in 
weight. 

To  account  for  all  these  discordant  changes  was  the  most 
difficult  part  of  all : it  was  indeed  easy  to  say,  that  combustion 
was  the  giving  out  of  an  inflammable  principle  to  the  air ; and 
to  say  concerning  respiration,  that  it  was  the  business  of  the 
air  to  take  away  continually  the  superabundant  phlogiston  of 
the  blood  ; but  how  a metal  should  pass  from  a mild  to  a most 


376 


OF  THE  BLOOD. 


acrimonious  and  caustic  state  ; and  above  all,  how  by  the  loss 
of  its  inflammable  principle  it  should  not  lose  in  weight,  but 
increase  in  weight ! This  was  the  Gordian  knot  which  they 
had  to  untie,  and  which  they  cut  lustily,  betaking  themselves, 
in  defiance  of  all  philosophy,  to  the  absurd  project  of  a prin- 
ciple of  absolute  lightness.  They  all  agreed  to  call  the  phlo- 
gistic principle,  a principle  of  absolute  levity;  and  thus 
their  doctrine  stood  for  many  years,  viz.  that  when  phlo- 
giston, or  inflammable  principle,  was  added  to  the  calx  of  any 
metal,  as  to  red  lead,  by  roasting  it  with  any  inflammable  bo- 
dy— the  metallic  lustre,  tenacity,  ductility,  were  restored,  and 
the  metal  became  lighter  withal,  because  it  now  had  within  it 
the  principle  of  levity.  But  that  when  by  heat  and  air  it  was 
calcined,  this  principle  was  driven  out,  and  then  the  metallic 
lustre,  tenacity,  ductility,  &tc.  were  lost  by  the  absence  of  the 
inflammable  principle  upon  which  they  all  depended  ; but  the 
weight  of  it  was  encreased,  for  the  principle  of  levity  was 
gone.  This  is  the  brief  abstract  of  the  theory  to  which  the 
very  best  chemists  have  addicted  themselves  down  to  the  pre- 
sent times. 

But  the  chief  perfection  of  modern  chemistry  is,  that  its 
apparatus  is  so  perfect,  that  it  can  employ  exactly  a certain 
quantity  of  air  in  calcining  a metal ; it  can  collect  that  air 
again  to  the  twentieth  part  of  a grain  ; it  can  prove  whether 
the  metal  has  really  been  giving  out  any  inflammable  principle 
to  the  air,  or  whether  it  has  received  matter  from  the  air,  and 
how  much  expressly  it  has  gained  or  lost.  Modern  chemis- 
try proves  to  us,  that  it  is  not  the  loss  of  any  principle  that 
endows  a metal,  for  example,  with  negative  powers  : but  the 
direct  acquisition  of  a new  principle,  which  endows  it  with 
positive  powers.  Thus  if  you  take  a quantity  of  mercury, 
and  expose  it  slowly,  that  is,  for  a long  time  to  heat  and  air, 
the  following  changes  take  place ; it  gradually  loses  its  metalic 
lustre,  the  upper  part  of  it  assumes  first  a yellow  and  then  a 
red  colour,  small  red  particles  are  seen  floating  on  the  sur- 
face of  the  mercury ; and  these  are  the  mercurius  precipita- 
tes per  se,  a most  acrid  calx  of  mercury.  If,  first,  you  esti- 
mate how  much  air  has  been  expended  during  the  process, 
you  find  that  the  weight  of  the  mercury  is  increased  in  exact 
proportion  ; if  you  put  that  calx  into  a gun-barrel,  put  the 
gun-barrel  into  the  fire,  and  by  mere  force  of  heat  drive  out 
this  air,  you  find  the  quantity  of  air  exactly  equivalent  to  the 
quantity  expended  in  the  process ; you  find  the  metal  grow 
lighter,  and  recover  its  metalic  qualities  and  lustre  in  propor- 
tion as  the  air  is  expelled.  In  short,  we  find  the  metal  hea- 
vier when  combined  with  air,  lighter  when  the  air  is  drives 


OF  THE  BLOOD. 


377 


out ; we  find  it  having  the  qualities  of  a metal  when  uncom- 
bined with  air, — when  combined  with  air  having  the  quali- 
ties of  a calx  : then  plainly  this  caustic  form  of  the  metal  is 
not  a negative  quality,  it  is  a positive  one,  proceeding  from 
the  infusion  of  this  new  principle  from  the  air. 

By  such  proofs  as  these  chemistry  has  explained,  in  a most 
philosophical  way,  how  all  these  phlogistic  processes,  as  they 
were  called,  depend,  not  on  the  abstraction  of  phlogiston,  but 
on  the  addition  of  a new  principle  : that  they  all  arise  from 
one  positive  power,  that  the  same  principle  gives  life  to  fuel, 
increase  of  weight  (and  other  effects  of  calcination)  to  metals, 
acidity  to  acids,  and  redness  to  the  blood.  These  are  all 
performed  by  one  power  ; they  are  all  essentially  one  pro- 
cess; they  are  all  effected  by  the  communication  of  one  sole 
principle,  viz.  the  basis  of  pure  air. 

Upon  our  atmosphere  and  its  surprising  harmony  with  all 
parts  of  nature  ; viuth  animal  and  vegetable  life  ; witb  water, 
metal,  acids,  and  all  the  solid  bodies  into  which  it  enters — 
much  more  depends  than  it  is  easy  to  conceive.  Could  we  have 
supposed  that  it  was  the  cause,  not  merely  of  life  in  all  living 
creatures,  but  almost  the  cause  of  all  the  properties  that  re- 
side in  the  most  solid  forms  ? Could  we  have  supposed  that 
the  air  rendered  heavy  bodies  heavier,  changed  metals  into 
the  most  caustic  substances,  converted  many  bodies  into  acids, 
changed  inflammable  air  into  the  pure  element  of  water, 
which  at  least  we  have  hitherto  conceived  to  be  pure? 
Yet  if  there  be  one  word  of  truth  in  chemistry,  all  this  is 
true. 

The  atmosphere  contains  various  gases  or  airs ; but  one 
only,  viz.  vital  air  or  oxygene  gas,  is  useful  to  respiration, 
combustion,  and  animal  life  ; that  purer  air  must,  like  eveiy 
other,  arise  from  some  solid  basis  : that  basis  cannot  be  shown 
in  any  substantial  form,  but  it  can  be  combined  with  many  va- 
rious bodies,  so  as  to  give  them  an  increased  weight  and  new 
qualities ; and  thence  we  presume  to  say,  whenever  we  see 
a body,  by  such  a process,  acquiring  such  qualities,  that  it 
acquires  tbem  by  absorbing  the  basis  of  pure  air ; for  pure 
air  is  nothing  but  this  presumed  basis  dilated  into  the  form  off 
air  by  heat ; and  when  it  combines  with  any  body,  it  gives 
out  its  heat ; so  that  in  all  these  processes  heat  is  produced. 
And  although  inflammable  bodies,  metals,  acids,  and  animal 
blood,  seem  very  distinct  from  each  other ; although  combus- 
tion, breathing,  calcination,  and  the  forming  of  acids,  are  pro-'* 
cesses  seemingly  very  unlike  ; yet  they  are  all  in  thcir.essential 
points  the  same,  viz.  a change  of  qualities  and  a production  of 
heat  in  consequence  of  the  absorption  of  pure  air. 
von,  I.  B b b 


378 


OF  THE  BLOOD. 


First,  when  an  inflammable  body  is  burnt  or  consumed  by 
fire,  the  basis  of  pure  air  is  combining  with  the  combustible 
body;  the  air  is  entering  into  a new  combination,  and  there- 
fore must  give  out  its  heat ; it  combines  rapidly,  gives  out  its 
heat  rapidly,  is  wasted  ; the  inflammable  body  burns  and  seem# 
to  be  consumed ; but  if  we  catch  that  air  which  escapes  from 
the  inflammable  body,  we  find  it  to  be  equal  exactly  to  the 
whole  weight  of  the  air  and  of  the  burning  body  that  have 
been  consumed  ; and  this  air  consists  of  two  parts,  viz.  of  the 
substance  that  was  burnt,  and  of  the  basis  of  pure  air.  Thus, 
for  example,  when  we  burn  charcoal  or  carbon,  the  whole 
substance  of  it,  weight  for  weight,  is  converted  into  an  air, 
w'hich  is  called  fixed  or  carbonic  acid  gas ; the  same  which  is 
discharged  from  stoves,  the  same  also  which  is  found  in  pits, 
the  same  which  oozes  through  the  ground  in  the  Grotto  del 
Cane,  the  same  which  floats  upon  the  surface  of  fermenting 
vats,  and  which  is  so  much  heavier  than  common  air  that  it 
can  be  taken  out  from  a vat  in  basons,  and  poured  from  dish 
to  dish.  Combustion,  then,  is  a process  which  consists  in  the 
rapid  assumption  of  the  basis  of  pure  air,  and  a consequent 
conversion  of  the  burning  body  into  an  air  or  gas  endowed 
with  peculiar  qualities  and  powers. 

If,  then,  the  oxygenation  of  the  blood  be  a process  like 
this,  it  must  differ  chiefly  in  degree ; it  might  in  certain  cir- 
cumstances become  too  rapid,  and  resemble  an  actual  com- 
bustion ; and  so  in  certain  circumstances  it  does,  for  our  at- 
mosphere is  so  tempered  that  no  more  than  27  parts  out  of 
100  consist  of  pure  air;*  the  rest  is  food  for  vegetables,  but 
not  fit  to  maintain  flame  or  animal  life.  This  is  the  reason 
that  even  burning  as  well  as  breathing  are  slow  processes,  and 
that  an  animal,  if  made  to  breathe  pure  air  or  vital  air  as  it 
is  called,  gets  oxygene  too  rapidly  supplied,  is  consumed  and 
inflamed  quickly,  and  dies. 

Secondly  the  process  of  calcination  is  the  same  in  all  me- 
tals ; it  also  is  an  assumption  of  the  pure  air,  or  rather  of  its 
basis,  with  a change  of  qualities  and  increase  of  weight:  if  you 
calcine  lead  slowly,  it  becomes  first  yellow,  then  orange,  then 
red  ; it  becomes  heavier,  so  that  from  100  pounds  o(  lead  you 
have  1 10  pounds  of  lytharge,  or  calx  of  lead : if  you  calcine 
mercury,  it  also  becomes  first  yellow,  then  red,  and  much 
heavier  than  at  first : if  you  distill  any  of  these  metals,  you  can 
by  heat  merely  drive  out  the  purest  air  from  them ; they  re- 
^ cover  their  brilliancy,  and  grow  lighter,  because  the  basis  of 
air  is  expelled.  The  basis  of  pure  air  is  expelled,  not  in  that 
solid  form  in  which  it  was  embodied  by  the  calx,  but  being 
now  combined  with  heat,  it  appears  in  the  form  ol  vital  air ; 

* TMe'nIy-one  by  weiglit  of  oxygene. 


OF  THE  BLOOD. 


379 


the  air  is  much  purer  than  that  of  the  atmosphere  which  was 
used  in  the  process,  because  the  metal  absorbs  or  appropriates 
to  itself  nothing  but  the  purest  air,  leaving  the  azotic  or  foul 
air  behind  ; and  finally,  if  you  wish  to  see  the  harmony  be- 
twixt combustion  and  calcination,  or  to  be  assured  that  calcina- 
tion is  truly  the  burning  of  a metal,  take  some  of  this  pure  air, 
which  is  three  times  purer  than  the  atmosphere,  and  raises  an 
intenser  flame;  plunge  into  it  a piece  of  iron  wire,  which  is 
made  red  hot ; and  this  wire  (which  would  only  have  wasted 
or  rusted  into  a calx  in  the  common  atmosphere)  will  in  the 
pure  air  burst  out  into  a brilliant  white  flame,  and  burn  entirely 
while  it  has  such  air ; nay,  some  metals,  as  zinc,  burn  even  in 
our  common  atmosphere  with  a most  brilliant  flame. 

From  this  second  process,  must  it  not  be  presumed  that  the 
principle  w hich  gives  an  increase  of  weight  and  such  singular 
properties  to  various  metals,  must  have  very  interesting  effects 
upon  the  blood  ? 

Thirdly,  it  is  from  this  principle  also  that  all  acids  are  form- 
ed ; and  as  oxyd  is  the  Greek  name  for  acid,  the  great  Lavo- 
sier  has  thought  fit  to  give  a name  to  the  basis  of  air,  or  that 
principle  which  is  obvious  only  when  operating  in  such  proces- 
ses as  these.  He  adds  m the  Greek  name  for  acid  that  verb 
which  implies  the  generation  of  any  substance;  he  calls  it 
thus  oxygene,  or  the  principle  which  generates  acids.  It  were 
easy  to  show  how  truly  this  great  point  is  supported  by  all  the 
particular  operations  in  chemistry  ; it  shall  be  sufificient  to  ob- 
serve a few.*  When  we  burn  sulphur  in  open  air,  it  seems  to 
be  consumed  ; but  when  we  burn  it  in  close  vessels,  still  giving 
a free  access  to  air,  we  find  it  converted  into  an  acid  the  most 
ponderous  of  all,  weighing  greatly  more  than  the  sulphur  from 
which  it  was  procured.  The  operation  is  done  in  close  ves- 
sels : nothing  can  pass  but  what  is  known,  and  nothing  is  more 
certain  than  that  the  w hole  of  this  wonderful  and  rapid  change 
is  the  mere  effect  of  the  sulphur,  which  is  an  acidifiable  base, 
assuming  the  acidifying  principle  by  which  alone  it  can  become 
an  acid.  Phosphorus  being  burnt  in  a close  glass  upon  the 
point  of  a wire,  the  vital  part  of  the  atmosphere  is  consumed, 
the  azotic  air  (which  the  ancients  mistook  for  their  phlogiston) 
remains,  the  whole  phosphorus  is  changed  into  phosphoric  acid, 
and  the  whole  acid,  when  weighed,  expressly  equals  the  phos- 
phorus which  was  burnt,  and  the  air  which  w'as  consumed  along 
with  it.  Nay,  arsenic,  which  is  a metal,  being  calcined,  is  con- 
verted into  a perfect  acid.  Thus  we  see,  first,  that  calcination 
is  a mere  combustion,  since  it  can  be  made  so  rapid  as  to  be 
attended  with  heat  and  flame ; next  we  see  that  acidification 

* To  this  doctrine  numerous  objections  occur : — oxygene  by  union  with  liydrogene  fornis 
water;  sulpluir  by  union  with  hydrngene  forms suipliuretted  hydrogene,  an  acid,  &c  &c. 


o80 


or  THE  BLOOD. 


is,  like  calcination,  attended  with  heat  and  flame,  and  an  acqui- 
sition  of  weight  and  of  properties  like  those  of  calces.  We 
see  some  metals  converted  into  proper  acids;  acids  and  me- 
tals mixing  in  qualities  with  each  other ; acids  and  metals  are 
both  acidificable  bases,  both  ai-e  capable  of  receiving  new  and 
similar  properties,  by  assuming  into  their  composition  the  ba- 
sis of  pure  air;  and  in  one  single  process  the  whole  set  of  phe- 
nomena are  exemplified,  for  in  burning  arsenic  we  have  com- 
bustion, calcination,  and  generation  of  acid,  alt  in  one  process, 
the  product  being  named  indifferently  oxyd  of  arsenic,  or 
white  calx  of  arsenic.*  , 

But  if  most  acidifiable  bases  be  thus  forced  by  combination 
to  forsake  their  solid  and  assume  their  aerial  form,  others  more 
singular  still  are  recalled  from  their  aerial  form,  and  condensed 
into  the  fluid  form  of  a strong  acid.  Thus  azotic  or  nitrogene 
air,  which  forms  the  great  bulk  of  our  atmosphere,  is  convert- 
ed by  oxygenous  or  pure  air  into  an  acid  form  ;f  it  becomes 
nitrous  acid,  nitric  acid,  nitrous  air,  strong  or  weak  according 
to  the  various  degrees  of  oxygenation  communicated  to  it ; 
and  thus  nitrous  air,  by  its  appetite  for  oxygene,  and  by  its 
change  of  colour  and  its  condensation,  whenever  it  takes  oxy- 
gene from  the  air,  makes  an  eudiometer  or  measure  for  the 
purity  of  the  air;  and,  according  to  the  purity  of  the  atmos- 
phere, more  turbidness  and  more  redness  is  produced  in  the 
nitrous  air,  and  a greater  loss  of  bulk,  which  may  be  marked 
on  a scale. 

The  oxydation  of  the  blood  makes  a fact  no  less  important 
in  physiology  than  those  are  in  chemistry ; for  as  there  are  va- 
rious marks  of  the  influence  of  oxygene  on  the  blood  itself, 
there  are  terrible  proofs  of  its  importance  in  the  system,  and 
how  miserable  the  person  is  who  has  imperfect  organs,  or  an  ill 
oxygenated  blood.J 

Nature,  disregarding  all  occasional  supplies,  as  by  the  ab- 
sorption of  the  skin,  the  assimilation  of  aliments,  &c.  has  ap- 
pointed one  great  organ  for  the  oxygenation  of  the  blood,  viz. 
the  lungs.  In  opening  the  breast  of  a living  creature  we  best 
see  the  connection  of  respiration  with  the  great  system;  but 

^ It  is  nPcessary  to  add  nitre  to  make  it  burn.  Tlie  result  is  not  directly  an  acid,  but  a 
neutral  salt  formed  of  tbe  arsenical  acid  joined  to  the  alkali  of  nitre';  without  the  help  of 
nitrous  acid  it  is  only  an  oxyd  or  imperfect  acid  ; and  it  is  necessary  to  use  the  hy  pei-oxyge- 
nated  muriatic  acid  for  communicating  to  it  a sufficiency  of  oxygene  to  constitute  it  a j.-er- 
feet  acid. 

f N.  B.  It  i.s  necessary  to  inclose  tliem  in  one  vessel,  and  to  pass  the  electric  spark 
through  them  that  they  may  unite. 

t Yet  ! must  here  again  observe  that  thei'e  are  no  decided  proofs  of  the  o.vydatinn  of  l!« 
blood.  C.  B. 


OF  THE  BLOOD. 


381 


it  is  out  of  the  body  that  we  can  best  understand  its  particular 
effects  upon  the  blooo. 

The  most  obvious  effect  of  air  is  its  heigbting  the  colour 
of  the  blood.  If  we  expose  blood  to  fixed  air,  or  azotic  air,  it 
continues  dark;  these  fluids  communicate  nothing,  they  have 
no  effect  on  the  colour  of  the  blood : when  we  expose  blood 
to  atmospheric  air,  it  assumes  a florid  colour , for  in  the  at- 
mosphere there  is  a large  proportion  of  oxygene  gas  : if,  lastly, 
we  expose  it  to  oxygene  gas,  the  purest  of  all  air,  it  grows 
extremely  florid ; and  whenever  it  changes  its  colour,  it  is  by 
absorbing  oxygene,  for  it  reduces  in  the  same  proportion  the 
quantity  of  air ; what  it  absorbs  is  the  oxygene  or  pure  air,  what 
it  leaves  is  mephitis,  unfit  for  combustion  or  animal  life.* 

Blood  when  exposed  to  the  air  becomes  red  chiefly  on  the 
surface,  it  remains  black  beneath,  but  by  turning  up  the  clot  to 
the  air  all  the  surfaces  become  red.  If  air  be  blown  into  a 
tied  vein,  the  blood  which  was  black  in  the  vein  becomes  flo- 
rid ; and  when  the  air  is  pressed  out  again,  it  becomes  black. 
If  the  air-pump  be  exhausted  over  a dish  of  blood,  the  blood 
becomes  dark  in  the  vacuum  ; and  it  becomes  florid  when  the 
air  is  allowed  to  rush  in  again.  If  you  expose  blood  in  a 
moist  bladder,  the  blood  is  oxygenated  through  the  walls  of 
the  bladder ; which  brings  this  experiment  as  close  as  may  be 
to  the  phenomenon  of  blood  oxygenated,  through  the  walls  of 
the  lungs.  Though  serum  or  milk  be  interposed,  or  urine, 
still  the  blood  is  oxygenated,  because  these  are  perfect  ani- 
mal fluids ; but  it  is  not  oxygenated,  if  oil,  mucilage,  or  mere 
water,  be  interposed. 

When  we  open  a Frog,  orNewt,f  or  other  amphibious  crea- 
ture, we  see  a long  and  slender  artery  accompanied  by  a slen- 
der vein,  running  from  top  to  bottom  along  the  whole  surface 
of  their  lungs;  and  while  their  heart  continues  to  beat,  we  see 
this  pulmonic  artery  black,  the  vein  red,  the  lungs  themselves 
most  delicate  and  pellucid,  like  the  swimming  bladder  of  a 
fish  : even  in  the  extremities  of  the  human  system  the  blood 
of  a vein  is  dark,  of  an  artery  red ; so  that  surgeons  distin- 
guish venous  and  arterial  haemorrhagies  in  this  way. 

From  these  facts  we  may  understand  why  the  blood  of  the 
Avonib,  of  sinuses,  of  varices,  and  of  all  stagnant  veins,  is  so 
offensive  and  black  ; and  why  that  blood  is  so  very  pure  and 
florid  which  is  coughed  up  from  the  lungs.  Is  not  the  face 
livid  in  apoplexies  or  strangulations,  in  hanging  or  drowning, 
in  fits  of  passion  or  of  coughing,  or  in  any  accident  which  in- 
terrupts the  lungs  ? The  face  of  a child  during  a paroxysm  of 

' Carbonic  acid  gas  is  formed;  the  absorption  of  pure  oxygene  is  doubtful. 

f See  Chap.  Ilf 


382 


OF  THE  BLOOD. 


the  hooping  cough,  is  it  not  completely  black  ? Is  not  the  hand 
livid  when  the  arm  is  compressed  or  tied  up,  and  its  blood  pre- 
vented from  returning  to  the  lungs  and  heart?  Are  not  tu- 
mours dark  coloured  from  dilated  veins  which  return  their 
blood  too  slowly  ? Are  not  these  mulberry  marks  which  are 
born  with  us  just  small  aneurisms  full  of  ill  oxygenated  blood  ’ — 
Then  this  first  effect  of  oxygenation  is  a reddening  of  the 
blood.  The  menstrual  blood,  the  blood  of  ecchymosis,  (as 
in  those  who  have  been  whipt,)  the  blood  of  aneurismal  bags, 
are  all  black ; and  the  blood  of  varices  is  so  very  black,  that 
the  ancients  said  they  were  filled  with  atrabilis  or  black  bile. 
The  stripes  inflicted  on  a soldier  as  a punishment  are  at  first  of 
the  most  lively  red,  but  soon  become  black. 

The  next  effect  of  oxygenation  is  the  endowing  the  blood 
with  a peculiar  power,  by  which  it  is  continually  operating 
upon  the  living  solid  : this  is  a power  which  it  is  continually 
losing ; which  it  is  every  moment  giving  up  to  the  solids  ; and 
which  no  other  process  but  respiration  can  restore.  This  sti- 
mulant power  the  blood  gradually  loses  as  it  circulates  round 
the  body ; it  is  quite  effete  when  it  returns  to  the  right  side 
of  the  heart : the  heart  of  a creature  never  moves^  if  we  allow 
its  lungs  to  lie  collapsed  ; but  the  heart  returns  to  act  the  very 
instant  that  pure  air  is  forced  into  the  lungs,  and  so  communi- 
cated to  the  blood.  This  stimulant  power  is  most  of  all  appa- 
rent when  w'e  force  a living  creature  to  breathe  nothing  but 
the  purest  air ; for  oxygenated  or  vital  air  makes  this  process 
too  rapid ; the  pulse  rises,  the  eyes  become  red  and  promi- 
nent, the  creature  seems  drunk  with  the  new  stimulus,  too 
great  for  its  system.  The  universal  heat  of  its  body  is  greatly 
increased,  the  eyes  are  turgid  and  red,  and  at  last  a sweat 
breaks  forth  all  over  it;  and  when  dead,  the  lungs  (it  is  said) 
are  mortified  or  inflamed.  But  whatever  the  marks  are, 
whether  these  signs  of  inflammation  be  really  true,  it  is  plain, 
since  the  creature  dies,  that  pure  air  is  fatal  by  a too  rapid 
oxygenation  of  the  blood.  If,  in  our  experiments  upon  a dy- 
ing animal,  we  inflate  the  lungs  with  mephitic  air,  the  heart 
does  not  act ; if  we  inflate  its  lungs  with  common  air,  the 
heart  begins  to  act ; if  we  Inflate  its  lungs  with  oxygene  air, 
the  heart  is  irritated  to  a still  more  powerful  action. 

If  vvfc  open  the  breast  of  a Frog  and  stop  its  breathing,  we 
observe,  first,  its  pulmonic  blood  florid,  and  the  heart  beating 
strongly  : secondly,  in  half  an  hour  the  pulmonic  blood  has 
become  dark,  and  the  heart’s  motion  has  grown  languid  ; in  a 
little  while  the  pulmonic  blood  becomes  black,  and  the  pulsa- 
tion of  the  heart  ceases:  and,  lastly,  the  trachea  of  the  Frog 


OF  THE  BLOOD.  383 

Seing  untied,  and  the  creature  allowed  to  breathe  again,  the 
blood  becomes  florid,  and  the  heart  acts. 

OF  THE  HEAT  OP  THE  BLOOD. 

The  next  effect  of  oxygene  is  said  to  be  the  communica- 
ting of  HEAT  to  the  lungs.  But  I suspect  that  if  the  small 
quantity  of  oxygene  which  can  enter  by  the  lungs  do  commu- 
nicate heat,  it  must  be  not  to  the  lungs,  nor  to  the  blood,  but 
to  the  whole  body  through  the  medium  of  the  blood.  There 
are  some  who  pretend  to  say,  that  when  they  draw  in  vital  air, 
they  feel  a genial  warmth  in  the  breast,  diffusing  itself  over  all 
the  body ; but  it  is  easy  to  feel  in  this  way,  or  any  way,  when 
a favourite  doctrine  is  at  stake,  while  those  who  know  nothing 
about  doctrines,  breathe  the  vital  air  without  any  peculiar  feel- 
ing which  they  can  explain. 

There  are  many  circumstances  which  make  it  hard  to  be- 
lieve that  there  is  in  consequence  of  the  oxydation  of  the 
blood,  any  remarkable  generation  of  heat  in  the  lungs.  Oxyd- 
ation of  the  blood,  out  of  the  body,  is  attended  with  no  in- 
crease of  heat,  and  yet  we  operate  on  a quantity  of  blood 
much  greater  than  that  which  circulates  through  the  lungs. 

To  suppose,  but  for  a moment,  that  all  the  heat  which 
warms  the  whole  body  emanates  from  the  lungs,  were  a gross 
error  in  philosophy  : it  were  to  suppose  an  accumulation  of 
heat  in  the  lungs  equal  to  this  vast  effect  of  heating  the  whole 
body.  But  were  it  so,  we  should  feel  a burning  heat  in  the 
centre,  a mortal  coldness  at  the  extremities,  and  marked  dif- 
ferences in  the  heat  of  each  part  in  proportion  to  its  distance 
from  the  lungs.  In  fevers,  we  should  feel  only  the  intense 
heat  of  the  centre ; we  should  be  distressed,  not  with  the 
heat  in  the  soles  of  the  feet  or  palms  of  tbe  hands,  or  in  the 
mouth  and  tongue;  we  should  feel  only  the  heat  of  the  lungs. 
When  the  limbs  alone  were  cold,  would  the  lungs  warm  them 
How  could  it  warm  them  up  to  the  right  temperature  without 
overheating  the  whole  body  When  a part  were  inflamed,  how 
could  the  heat  go  from  the  lungs,  particularly  to  that  point,  and 
rest  there  ? 

From  the  lungs  the  heat  could  not  be  regularly  diffused; 
for  in  almost  all  the  Amphibiae  the  lungs  are  far  distant  from 
the  centre  of  the  body,  and  could  not  communicate  any  de- 
gree of  heat  to  the  extremities  without  the  g^reatest  waste ; 
they  would,  according  to  this  theory,  have  lungs  for  crying 
with,  if  they  pleased  to  cry,  but  by  no  means  for  distributing^ 
heat. 

But  in  reflecting  upon  this  most  diflicult  of  all  subjects,  the 


384 


OF  THE  BEOOD. 


generation  of  heat  in  the  living  body,  many  things  are  to  be  ta- 
ken into  the  calculation,  which  seem,  on  the  slightest  glance, 
to  be  far  more  important  than  this  deposition  of  oxygene  from 
the  blood.  It  is  a law  of  nature,  to  which,  as  far  as  we  know, 
no  exception  is  found,  that  a body,  while  it  passes  from  an 
aerial  to  a fluid  form,  or  from  a fluid  to  a solid  form,  gives  out 
heat.  Now,  what  is  the  whole  business  of  the  living  system 
but  a continual  assimilation  of  new  parts,  making  them  con- 
tinually pass  from  a fluid  into  a solid  form  ? The  whole  nourish- 
ment of  the  body  goes  on  in  the  extreme  vessels,  and  is  a 
continual  assumption  of  new  parts.  The  extreme  vessels  are 
continually  employed  in  forming  some  acids,  which  appear 
naked  in  the  secretions ; in  forming  oxyds,  as  the  fat  and  the 
jellies  of  the  membranous  and  white  parts ; in  the  various  de- 
positions of  muscle,  bone,  tendon.  Sic.  for  these  are  all  con- 
tinually absorbed,  thrown  off  by  the  urine,  and  incessantly  re- 
newed. They  are  continually  employed  in  filling  all  the  inter- 
stices of  the  body  with  a bland  fluid  or  halitus ; they  are  con- 
tinually employed  in  forming  secretions  of  various  kinds.  In 
performing  all  this  the  power  of  the  vessels  may  do  much  ; 
but  the  ultimate  effect  in  each  process  must  be  a chemical 
change,  and  perpetual  changes  will  produce  a constant  heat. 
Place  the  organ  and  focus  of  this  animal  heat  in  the  centre  of 
the  body,  and  you  are  embarrassed  in  a thousand  difficulties ; 
allow  this  heat  to  arise  in  each  part  according  to  its  degree  of 
action,  and  each  part  provides  for  itself. 

But  how  then,  some  will  say,  shall  this  heat  be  regulated 
I say  plainly  by  the  heart  and  lungs.  The  lungs  regulate  the 
stimulant  power  of  the  blood,  the  heart  regulates  the  action 
of  the  arteries,  in  so  far  as  regards  the  stimulus  of  fulness  and 
distention  ; and  with  these  to  regulate  the  centre,  nothing  can 
alter  the  heat  of  the  extremities  except  partial  actions,  that  is, 
disease. 

I will  conclude  then,  that  oxygene,  if  it  do  communicate 
heat,  does  so,  “ not  to  tlie  lungs,  nor  to  the  blood,  but  to  the 
whole  body  through  the  medium  of  the  blood.” 


OF  THE  RESPIRATION  OF  ANIMALS. 

The  effects  of  oxydatlon  then  are,  to  redden  the  blood,  to 
renew  its  stimulant  power,  and  to  communicate  heat,  not  so 
much  to  the  blood,  as  to  the  whole  body  through  the  medium 
of  the  blood,  and  to  assist  in  the  secretions  and  chemical 
changes  which  are  incessantly  going  on  in  all  parts  of  the 
system.  This  is  accomplished  by  the  perpetual  and  rapid 


OF  THE  BLOOD. 


385 


motion  of  the  blood  through  the  lungs ; and  there  it  is  ex- 
posed to  our  atmosphere,  which  is  a mixed  fluid  very  diflerent 
from  what  we  at  first  conceive,  or  what  our  ignorant  wishes 
might  desire  to  have  it ; not  consisting  merely  of  air  fit  to  be 
breathed,  but  for  the  greatest  part  formed  of  an  air  which  is 
most  fatal  to  animal  life,  whence  it  has  the  name  of  Azotic 
Gas.  Of  an  hundred  measures  of  atmospheric  air,  we  find 
twenty-seven  only  to  consist  of  vital  or  pure  air,  that  is  oxygene ; 
seventy-two  consist  of  azotic  air,  or  nitrogene,  as  it  is  called, 
fatal  to  animal  life  ; and  one  measure  only  is  fixed  air,  or  car- 
bonic acid,  which  is  also  an  unrespirable  air.  But  of  these 
twenty-seven  parts  of  pure  air,  seventeen  parts  only  are  af- 
fected by  respiration  ; so  that  in  respiration  we  use  much  less 
than  a fifth  part,  even  of  the  small  quantity  of  air  which  we 
take  in  at  each  breath. 

The  change  of  the  air  by  respiration  is  this  chiefly ; that 
the  quantity  is  diminished  by  the  abstraction  of  a part  of  the 
oxygene  ; that  there  is  formed  a quantity  of  carbonic  acid  gas 
by  the  union  of  the  carbon  of  the  blood  with  the  oxygene  res- 
pired ; and  that  there  is  discharged  along  with  these  a quantity 
of  watery  halitus.  Therefore  atmospheric  air,  after  it  has 
been  breathed,  is  found  to  have  suffered  these  changes  : First, 
It  contains  now  a considerable  proportion  of  carbonic  acid, 
which  is  easily  discovered,  and  even  weighed ; because  wdien 
a caustic  alkali  is  exposed  to  it,  the  alkali  absorbs  the  fixed 
air  and  becomes  mild.  Secondly,  It  has  less  of  the  vital  air, 
as  is  easily  ascertained  by  the  eudiometer  which  measures  the 
purity  of  the  whole  : And,  thirdly.  All  that  remains  is  merely 
azotic  air,  unfit  for  animal  life,  or  for  supporting  flame.  The 
oxygene,  then,  in  part  unites  itself  with  the  blood : in  part  it 
forms  fixed  air  by  combining  with  the  carbon  of  the  lungs  ; in 
part  it  forms  water  by  combining  with  the  hydrogene  of  the 
blood.  Respiration  frees  the  blood  of  two  noxious  principles, 
the  hydrogene  and  carbon  ; and  it  insinuates  a new  principle, 
viz.  the  oxygene,  into  the  blood.* 

* Such  has  been  the  opinion  of  chemists  up  almost  to  the  present  day ; but  the  rapid 
changes  of  opinion,  and  indeed  of  whole  systems,  and  the  confusion  into  which  the  dis- , 
coveries  of  to-day  throws  the  result  of  all  preceding  labours,  would  almost  provoke  an 
anatomist  to  put  out  of  Ills  system  the  chemical  discussion  altogether,  until  the  masters  of 
that  science  have  better  arranged  their  materials,  and  have  arrived  at  acknowledged  prin- 
ciples. More  careful  experiments  have  proved  that  the  volume  of  air  expired  is  the  same 
with  that  inspired, — ^the  respired  air  differing  only  in  the  variable  proportion  of  carbonic 
acid  gas,  and  aqueous  vapour ; that  all  the  oxygene  taken  from  the  atmosphere  by  respi- 
ration, is  consumed  in  the  formation  of  the  carbonic  acid  gas  found  in  the  respired  air  ; and 
that  the  heat  evolved  by  respiration  is  not  the  heat  of  the  body,  but  the  heat  of  tlie  air 
respired,  latent  before,  and  now  become  sensible,  owing  to  a change  of  capacity  in  the 
gases. 

The  change  produced  in  the  blood  during  the  circulation  in  the  lungs,  is  simply  to  free  it 
of  the  superabundance  of  carbon  with  which  it  is  loaded  in  consequence  of  the  secretions 
performed  in  the  extreme  vessels  of  the  system  of  the  body. 

As  to  the  heat  of  the  body,  chemists  seem  to  have  agreed,  that  full  confidence  is  to  be 

vor..  I.  C c c 


386 


OF  THE  BLOOD. 


Nature  has  appointed  but  a small  proportion  of  vital  air  for 
our  use  ; our  atmosphere  is  so  constituted  as  to  hold  but  a 
fourth  part  of  vital  air,  and  of  that  small  proportion  one  half 
only  is  used  in  the  lungs.  We  see  by  this  how  necessary  this 
contamination  of  our  atmosphere  is  which  seems  so  unfavour- 
able to  life  ; nature  intended  that  we  should  breathe  slowly 
a modified  atmosphere  ! With  nothing  but  the  purest  air  to 
breathe,  our  life  would  be  quickly  consumed,  like  that  defla- 
gration of  iron,  which  is  so  rapid  in  vital  air,  while  it  burns  so 
moderately  and  slowly  in  the  common  air. 

These  assistances  which  we  have  from  chemistr)^  are  but  a 
promise  of  what  that  science  may  do  ; nothing  of  all  that  we 
know  conceming  the  chemistry  of  the  blood  is  either  perfect 
or  sure  : we  have  our  expectations  still  of  seeing  things  more 
completely  explained  : but  our  expectations  are  not  like  those 
of  Mr,  Moises,  who,  in  a certain  dissertation  on  the  blood, 
seems  so  full  of  his  new  lessons  in  chemistry,  and  so  confident 
of  his  future  achievements  in  that  science,  as  to  expect  that 
muscular  motion  shall  be  very  thoroughly  explained,  and  that 
it  will  be’found  to  be  nothing  else,  in  all  the  world,  but  “ an 
explosion  of  hydrogene  and  oxygene,”  and  God  knows  what ! 
but  it  is  after  the  manner  of  “ a steam  engine and  if  his 
scheme  holds,  they  are  to  be  fired  off  “ by  means  of  the 
nervous  electricity  of  Galvani  !”* 


OF  THE  MEMBRANES  OF  CAVITIES,  AND  PARTICULARLY  OF 
THE  MEMBRANES  OF  THE  THOKAX.f 

Every  part  of  an  animal  body,  with  the  exception  of  the 
fluids,  the  matter  of  the  nerves,  of  the  muscles,  and  of  the 

put  in  tlin  pxperimenis  anti  opinions  of  Dr.  Crauforel,  v.-hose  theories  l)ave  been  criticiscrl  in 
Ibnner  editions  of  tliis  work.  The  brief  abstract  of  ivlilcli  doctrine  is  this.  Tlie  venom 
blood  has  less  capacity  for  retaining  heat  than  arterial  blood.  AVhen  the  blood  of  the 
arteries  of  the  body  is  converted  into  purple  blood,  and  enters  the.  small  veins,  beat  is  let 
loose  and  becomes  sensible,  giving  warmth  and  a stimulus  to  the  operations  of  the  animal 
economy.  When  this  venous  blood  is,  in  the  round  of  the  circulation,  brought  back  to  the 
lungs,  while  it  throws  out  its  siiperaliuiidant  carbon,  and  when  this  carbon  unites  with 
oxygene  of  the  air  res|ii.red,  and  forms  carbonic  acid,  heat  is  evolved.  Wliile  this  action 
of  respiration  is  producing  heat,  it  is  also  forming  of  venous  blood  artei'ial  blood.  And  as 
the  ai'lnrial  bloorl,  in  its  conversion  into  venous  blood,  gave  out  heat,  so  now,  being  re- 
converted into  artei'ial  blood,  it  takes  up  brat,  and  that  is  not  sensible  heat,  but  latent, 
rhere  is,  therefore,  no  central  fire,  as  it  were,  in  the  breast,  and  yet  there  is  a source  of 
heat  to  the  whole  body  from  the  o[jeration  of  the  lungs.  And  what  degree  of  heat  more 
ihan  necessary  for  the  conversion  of  the  blood,  and  which  might  be  injurious,  i.-  expended 
in  forming  the  vapour  exhaled  from  tlie  lungs.  C.  B. 

Vide  page  236. 


f By  Charles  Bell. 


OF  THE  MEMBRANES  OF  CAVITIES. 


387 


bones,  is  resolvable  into  membrane  by  masceration  and  the 
contrivances  of  the  anatomist.  1 he  fine  web  which  supports 
the  retina  in  the  eye,  and  the  strong  cord  on  which  the 
gastrocnemius  acts,  are  formed  of  the  same  kind  of  tissue,  the 
cellular  texture.  Another  remarkable  circumstance  is,  that 
this  cellular  texture  no  where  terminates,  or  that  the  mem- 
branes of  the  body  are  every  where  in  continuity.  If,  for 
example,  we  begin  our  investigation  with  the  tendon  of  a 
muscle,  we  shall  find  that  it  is  resolvable  into  a twisted  mem- 
brane, we  may  trace  this  membrane  into  the  muscle,  and  we 
shall  find  it  enveloping  the  muscular  fibres,  and  extending 
through  the  muscle,  and  uniting  again  to  form  the  tendinous 
insertion  of  the  muscle  into  the  bone.  From  the  tendon  the 
continuation  is  direct  to  the  periosteum  ; the  periosteum  is  con- 
tinued into  the  ligaments  and  capsule  of  the  joint ; from  this 
again  we  may  trace  the  fascia,  and  intermuscular  septa.  These 
firmer  structures  we  shall  find  loosening  into  the  common  cel- 
lular texture,  and  that  texture,  as  has  been  already  explained, 
may  be  traced  over  the  whole  animal  frame. 

But  we  have  now  particularly  to  consider  the  structure 
and  connections  of  the  membranes  of  the  great  cavities  of 
the  body;  and,  in  the  first  place,  the  membranes  of  the 
thorax. 

A membrane  is  an  expansion  or  web  of  animal  matter, 
having  extension  with  a scarcely  measureabie  thickness  : it 
■ has  one  surface,  free  or  disunited,  and  smooth,  and  lubri- 
cated with  a secreting  fluid.  It  has  the  other  surface  rough 
and  attached,  being  more  like  the  common  cellular  texture, 
of  which,  in  fact,  the  whole  membrane  is  a composition. 

The  membranes  of  the  viscera  are  arranged  in  two  grand 
divisions,  viz.  the  mucous  membranes,  and  the  serous  mem- 
branes ; all  of  which  are  remarkable  for  their  extent  of  surface, 
but  especially  the  former.  The  difference  of  the  two  great 
classes  of  membranes  is  referable  to  the  nature  of  their  secre- 
tions. The  object  of  the  secretions  is  to  prevent  adhesion  of 
contiguous  surfaces,  which  is  most  effectually  done  by  the  mu- 
cous secretion.  But  as  the  mucous  secretion  is  not  readily 
soluble  nor  prepared  for  absorption  ; as  when  secreted  it  must 
be  thrown  off  from  the  surface,  and  urged  out  of  the  body 
altogether;  it  is  obvious  that  this  is  a secretion  calculated 
solely  for  the  membranes  which  are  open,  and  from  which  it 
may  be  discharged. 

The  serous  fluid  is  finer,  more  watery,  and  very  readily 
absorbed  ; so  that  it  is  supplied  to  moisten  the  surfaces  of  shut 
sacs,  and  membranes  which  are  continuous  and  have  no  out- 
let, such  as  those  lining  the  great  cavities.  But  if  there  be 


388 


OF  THE  MEMBRANES  OF  CAVITIES. 


any  tendency  to  inflammation  on  tliese  surfaces,  they  are 
more  prone  to  adhesion  than  the  mucous  membranes,  be- 
cause the  inflammatory  action  will  more  quickly  convert  se- 
rum to  coagulable  lymph  (which  is  the  medium  of  adhesion) 
than  it  will  the  mucous  secretion. 

The  mucous  membrane  is  tbe  continuation  of  the  skin  ; it 
is  every  where  continuous,  but  it  admits  of  a natural  division, 
viz.  J.  The  mucous  lining  of  the  lungs;  2.  The  mucous 
lining  of  the  alimentaiy  canal,  and  the  ducts  which  open  into 
it ; and,  3.  The  mucous  lining  of  the  urinary  organs. 

We  may  trace  the  first  from  the  nostrils  up  into  the  cavities 
of  the  nose,  and  from  that  into  the  lining  membrane  of  the 
cells  of  the  face.  We  may  then  trace  it  backwards  into  the 
throat,  into  the  larynx,  the  trachea,  the  bronchi,  and,  finally, 
into  the  bronchial  cells,  an  extent  perhaps  equal  to  the  whole 
surface  of  the  body. 

To  trace  these  continuous  surfaces  is  not  an  idle  minute- 
ness ; for  we  require  to  know,  that  inflammation  will  creep 
along  the  surface  by  a prevailing  action,  which  has  got  the 
name  of  continuous  sympathy.  Thus  we  are  sensible  in 
catarrh  of  a sense  of  pain  and  weight  in  the  forehead,  com- 
mencing with  a dryness  of  the  cavities  of  the  nose ; then  we 
have  increase  of  secretion,  and  tickling  in  the  larynx  ; this  is 
followed  by  pain  and  a sense  of  rawness  in  the  throat ; lastly,  we 
have  pain  in  the  chest,  or  an  uneasy  tickling  sensation  in  the 
very  margin  of  the  lungs,  and  thus  the  inflammatory  action 
terminates  only  with  the  extremity  of  this  long  line  of  con- 
nection. 

The  second  division  of  the  mucous  membrane  is  the  lining 
membrane  of  the  mouth,  which  we  trace  into  the  asophagus, 
into  the  stomach,  into  the  intestines ; and,  after  a course  of 
full  seven  times  the  length  of  the  body,  it  appears  on  the 
verge  of  tbe  anus,  terminating,  as  it  began,  in  the  skin  ; and 
along  the  whole  of  this  mucous  lining  we  may  sometimes  trace 
the  course  of  inflammatory  action.  An  erysipelatous  blush, 
visible  in  the  throat,  will  sometimes  take  its  course  in  a very 
dangerous  manner,  over  the  whole  extent  of  the  canal,  even 
to  the  anus. 

The  third  division  of  this  membrane  is  where  the  fore-skin 
is  reflected  over  the  extremity  of  the  penis  into  the  urethra  ; 
here  the  mucous  secretion  commences,  and  it  characterizes 
the  whole  extent  of  the  canal,  tracing  it  through  the  bladder 
to  |the  pelvis  of  the  kidnies. 

Thus  we  shall  find,  that  the  mucous  membranes  form  the 
internal  surface  of  all  the  hollow  viscera,  and  now  we  shall  also 
see  that  that  the  serous  membranes  form  all  the  outward  sur- 


OF  THE  PLEURA. 


389 


face  of  the  same  viscera.  The  course  of  the  serous  mem- 
branes are,  however,  by  no  means  so  simple  nor  so  easily 
comprehended  by  the  student  as  that  of  the  mucous  mem- 
brane. I shall  at  present  confine  myself  to  the  anatomy  of  the 
membranes  of  the  thorax  or  chest. 


OF  THE  PLEURA. 

The  thorax  is  the  superior  cavity  of  the  trunk,  and  contains 
the  heart  and  great  vessels,  the  lungs,  and  the  thymus  gland: 
it  transmits  into  the  abdomen  the  oesophagus  and  nerves  ; and 
these  parts  are  involved  and  supported  by  the  processes  of  the 
pleura. 

The  pleura  is  the  fine  serous  membrane  which  lines  the  two 
cavities  of  the  chest,  and  is  reflected  upon  the  lungs.  We  shall 
consider  it  first  as  it  lines  the  ribs  (and  where  it  is  called 
PLEURA  cosTAHs  ;)  2.  then  as  it  is  reflected  on  the  diaphragm  ; 
3.  as  it  forms  the  septum  dividing  the  chest;  4.  as  it  is  re- 
flected to  cover  the  lungs  (where  it  is  the  pleura  pul- 

MONALIS.) 

The  pleura  costalis  is  the  lining  of  the  walls  of  the  chest. 
These  walls  consist  of  the  ribs,  their  cartilages,  and  the 
sternum,  their  interstices  being  filled  up  with  the  intercostal 
muscles.  The  lining  membrane  of  course  is  attached  in 
part  to  the  inside  of  the  ribs,  in  part  to  the  muscular  tex- 
ture which  intervenes.  It  is  a simple  membrane ; for  so  we 
call  it,  although  like  every  other  membrane  it  may  be  di- 
vided into  layers  of  cellular  membrane.  On  its  outer  surface 
it  is  most  loose  and  cellular  in  its  textui’e  ; on  the  surface  to- 
wards the  cavity  it  is  smooth  and  bedewed  with  secretion,  and 
is  consequently  unattached.  The  pleura  lining  the  ribs  is 
very  thin,  and  is  immediately  attached  to  the  periosteum. 

As  the  ribs  and  sternum  form  the  walls  of  the  chest  on  the 
lateral  and  foreparts,  the  diaphragm  forms  the  floor  of  divi- 
sion betwixt  the  cavity  of  the  chest  and  the  lower  cavity,  the 
abdomen.  From  the  ribs,  the  membrane  is  reflected  upon 
the  diaphragm,  to  which  it  adheres ; and  .fi'om  the  diaphragm 
and  lateral  parts  of  the  chest,  it  is  reflected  to  form  the  di- 
vision of  the  chest  which  is  called  mediastinum  ; which  com- 
pletes the  circle  of  connections,  as  far  as  relates  to  the  lateral 
cavity  of  the  chest. 


.590 


OF  THE  PLEURA. 


i'LAN  1.  plan  2, 


In  the  first  plan  here,  the  dotted  line  represents  the  course 
of  the  pleura,  in  a supposed  section  of  the  chest.  Two  late- 
ral cavities  are  seen  with  a partition  ; that  partition  or  septum 
is  the  mediastinum,  and  passes  from  the  spine  to  the  sternum, 
dividing  the  chest  into  two  lateral  cavities.  The  second  plan 
shows  the  manner  in  which  the  pleura  is  reflected  to  cover  the 
lungs  and  form  the  pleura  pulmonalis  : a dotted  line  still  marks 
the  course  of  the  membrane  ; and  here  we  may  observe,  that 
when  the  pleura  has  formed  the  septum, 'called  mediastinum, 
it  is  there  again  reflected  over  the  vessels  going  to  the  lungs, 
and  covering  the  vessels  protects  them,  and  forms  what  is  call- 
ed the  ligament  of  the  lungs.  Tracing  the  membrane  in  its 
course,  w'e  do  not  find  that  it  terminates  any  where ; we  find 
that  it  is  every  where  continuous,  and  that  the  pleura  pulmo- 
nalis and  pleura  costalis  are  the  same  continued  surface  of 
membrane. 

But  in  these  plans  a liberty  is  taken  to  represent  the  lungs 
shrunk,  and  leaving  the  sides  of  the  chest,  a thing  which  never 
takes  place  in  nature.  This  is  done  that  my  reader  may  fol- 
low the  line  distinctly ; properly  the  surface  of  the  lungs, 
(that  is,  the  pleura  pulmonalis,)  and  the  inner  surface  of  the 
ribs,  (the  pleura  costalis,)  should  have  been  in  contact ; for  al- 
though we  continually  speak  of  the  cavity  of  the  chest,  yet 
there  is  no  cavity  but  in  disease,  or  when  by  wounds  the  air 
is  permitted  to  escape  from  the  lungs,  and  then,  indeed,  the 
circumstances  are  as  represented  in  this- plan;  for  the  lungs 
leaving  the  side  of  the  chest,  there  is  a cavity  which  is  then 
filled  with  air. 

The  1st  Plan  shews  the  two  cavities  of  the  thorax  formed  by  the  pleura  costalis,  and  the 
septum  or  mediastinum  formed  by  tl'.e  meeting  of  the  membranes. 

The  2d  Plan  shews,  by  the  continuation  of  the  dotted  line,  how  the  pleura  costalis  ir 
continued  into  the  pleura  pulmonaHs. 


OF  THE  PLEURA. 


39  i 

When  we  trace  the  raembrane  of  the  ribs  over  the  lungs,  we 
comprehend  how  the  smooth  and  proper  surface  of  the  one 
is  internal,  and  the  other  external ; and  yet  that  these  surfaces 
are  continuous  and  the  same.  We  understand  too  how  the 
surface  of  the  pleura  pulmonalis  and  costalis  are  in  close  con- 
tact, and  yet  do  not  adhere,  and  that  consequently  freedom  is 
given  to  the  motion  of  the  lungs.  At  least,  if  in  respiration 
the  lungs  do  not  move  from  the  sides  of  the  chest,  they  are 
not  prevented  by  the  adhesion  of  the  pleura,  when  in  a healthy 
and  natural  state  ; but  by  a circumstance  already  in  part  ex- 
plained. The  lungs  cannot  recede  from  the  pleura  covering 
the  ribs,  because  no  air  can  be  admitted  to  fill  the  space 
which  would  be  then  necessarily  formed  betwixt  the  lungs  and 
ribs. 

The  LIGAMENTS  of  the  lungs  are  understood  when  my  read- 
er comprehends  the  manner  in  w'hich  the  pleura  is  reflected 
from  the  ribs  over  the  spine,  and  from  the  spine  over  the  great 
vessels  and  over  the  lungs.  Where  this  reflection  of  the  pleu- 
ra takes  place,  embracing  the  tubes  and  vessels  going  to  the 
substance  of  the  lungs,  it  forms  ligamentous  roots,  the  only 
natural  connection  of  the  lungs  to  the  chest. 

The  MEDiASTi.NUM  is  a partition  dividing  the  great  cavity 
of  the  chest  into  two  lateral  parts  : it  is  stretched  from  spine 
to  sternum.  This  is  a common,  and  it  may  be  a true  descrip- 
tion of  the  mediastinum  as  far  as  it  goes,  yet  it  is  a most  im- 
perfect one.  This  partition  of  the  thorax  is  esteemed  a pro- 
vision for  our  safety,  worthy  of  all  admiration ; and  so  indeed 
it  is.  But  when  it  is  said,  that  this  partition  provides  that  a 
man,  being  diseased  in  the  lungs  of  one  side,  or  wounded  be- 
twixt the  ribs  of  one  side,  may  still  breathe  with  the  other, 
I would  venture  to  say,  that  it  is  a wrong  reading  in  that  vo- 
lume which  it  ought  to  be  our  pride  to  preserve  pure.  Every 
motion  of  the  natural  system  has  its  proper  check ; every  de- 
licate part  has  its  guard  against  the  violent  motions  of  the  na- 
tural system  ; and  is  constituted  with  a due  provision  against 
the  injuries  we  are  liable  to  in  a state  of  nature.  But  nature 
had  it  not  in  contemplation  that  we  should  be  exposed  to  the 
gun  and  bayonet,  nor  can  I think  with  a celebrated  anatomist 
that  she  has  provided  for  sustaining  the  prolonged  existence  of 
him  who  is  slowly  wasted  by  pulmonary  consumption-  I can- 
not believe  that  there  is  either  in  the  foramina  of  the  heart, 
or  the  mechanism  of  the  chest,  a provision  against  tbe  ^ffects 
of  disease.  I have  therefore  to  show  that  the  mediastinum 
has  a reference  to  the  support  of  the  heart  and  great  vessels, 
against  the  unequal  pressure  to  W'hich,  wnthout  this  guard  they 
would  be  exposed  in  the  necessary  and  natural  changes  to 


392 


OF  THE  MEDIASTINUM. 


which  the  body  is  subject  in  health.  But  I have  said  that  the 
description  of  the  mediastinum  is  imperfect;  and  really, 
though  seemingly  simple,  it  is  difficult  to  represent  by  words 
the  connection  of  the  membranes  of  the  thorax. 

The  two  distinct  sacs  of  the  pleura,  each  forming  a lining 
membrane  to  the  two  sides  of  the  thorax,  approach  towards 
the  centre  of  the  cavity,  and  would  absolutely  unite  but  for 
the  intervention  of  the  heart  and  its  appendages.  And  so  in- 
deed it  is,  that  anterior  and  posterior  to  it,  these  membranes 
nearly  touch.  Where  the  sacs  of  the  pleura  approach  each 
other  anterior  to  the  heart,  they  form  the  anterior  mediasti- 
num ; and  in  the  same  manner  behind  the  heart  and  near  the 
spine,  they  form  the  posterior  mediastinum. 

The  anterior,  or  pectoral  mediastinum,  has,  in  the  embrace 
of  the  membranes,  much  cellular  membrane ; and  when  in 
dissection  we  raise  the  sternum,  this  loose  cellular  membrane 
allows  the  pleura  to  be  drawn  separate  so  as  to  form  a cavity, 
which  cavity  did  not  previously  exist.  The  anterior  medias- 
tinum contains  the  thymus  gland,  some  absorbent  glands,  a 
considerable  trunk  of  the  lymphatic  system,  which  has  been 
called  the  ductus  thoracicus  anticus. 

The  posterior  mediastinum,  called  sometimes  dorsale, 
contains  the  extremity  of  the  trachea  and  part  of  its  branches 
called  bronchi,  and  part  of  the  pulmonic  artery  and  veins ; the 
oesophagus,  for  the  greater  extent  of  its  course,  the  descending 
aorta,  and  the  great  trunk  of  the  absorbents,  the  thoracic  duct, 
the  eighth  pair  of  nerves,  and  the  dorsal  lymphatic  glands. 

Both  the  mediastina  are  a little  towards  the  left  side,  and 
the  posterior  one  is  much  the  longest. 

I now  leave  authority,  and  proceed  to  describe  the  more  im- 
portant connections  of  the  membranes  of  the  chest  with  the 
heart  and  great  vessels.  The  pleura,  which  is  a very  thin  and 
weak  membrane  where  it  invests  the  lungs  or  adheres  to  the 
inside  of  the  ribs,  is  particularly  strong  where  it  is  reflected 
from  the  diaphragm.  And  from  the  diaphragm  to  the  upper 
and  more  contracted  part  of  the  chest,  all  along  the  tract  of 
the  cava,  it  is  of  a ligamentous  firmness,  and  is  more  like  a 
fascia  or  tendon  than  those  layers  of  cellular  tissue,  which 
have  of  late  got  that  name  in  connection  with  the  subject  of 
hernia.  Towards  the  upper  part  of  the  chest,  the  pleura,  or 
rather  the  mediastinum,  covers  and  embraces  the  branches  of 
the  cava,  and  posteriorly  it  covers  and  protects  the  aorta  and 
thoracic  duct ; in  short,  were  it  not  the  fear  of  confounding 
the  ideas  of  the  younger  student,  I would  say,  that  this  struc- 
ture of  membranes  excludes  all  but  the  lungs  from  the  cavity 
of  the  chest ; and  consequently  from  the  effect  of  the  chest’s 


OF  THE  MEDIASTINUM. 


393 


jnotion  in  respiration.  How  the  respiration  does  not  affect  the 
veins  and  cavities  of  the  heart,  will  now,  I trust,  he  easily  con- 
<;eived,  and  consequently  the  use  of  the  mediastinum  be  un- 
derstood. 

But  before  I proceed  further,  I must  here  observe  that  the 
pleura,  where  it  is  reflected  to  form  the  mediastinum,  is  dou- 
ble ; that  is,  the  cellular  texture  acquires  a different  structure, 
has  a ligamentous  firmness,  and  performs  the  ofiice  of  a fascia 
around  the  vessels,  an  ofiice  which  could  not  have  been 
done  by  the  mere  reflection  of  the  lining  membrane  of  the 
chest. 

The  enlarged  capacity  of  the  thorax  in  every  direction,  the 
raising  the  of  the  ribs,  the  thrusting  out  of  the  sternum,  is 
attended  with  the  contraction  and  sinking  the  arch  of  the  dia- 
phragm. But  this  motion  which  expands  the  cells  of  the 
lungs,  and  draws  the  air  into  them,  would  disorder  the  heart’s 
motion,  would  cause  a lodgement  of  the  blood  and  distention 
of  the  great  veins  and  sinues,  were  they  under  the  influence 
of  the  motion  of  respiration.  But  the  diaphragm  moves  only 
on  its  lateral  parts,  or  it  is  checked  and  intercepted  at  the 
middle  part  by  the  connections  of  the  mediastinum.  In  pro- 
portion as  the  lateral  cavities  of  the  chest  and  the  lungs  con- 
sequently suffer  the  influence  of  this  expansion  of  the  chest, 
and  have  the  pressure  taken  from  them,  (which  bore  against 
the  weight  of  the  atmosphere,)  the  parts  contained  in  the 
mediastinum  suffer  pressure  by  the  action  of  the  diaphragm 
and  rising  of  the  sternum.  If  the  veins  near  the  heart  were 
exposed  to  the  same  influence  that  the  lungs  are,  they  would 
be  subject  to  the  same  change  of  quantity  of  what  they  con- 
tain ; the  blood  would  be  accumulated  in  inspiration,  and  forced 
out  from  them  in  expiration,  and  the  regular  action  of  the 
heart  interrupted  or  disturbed. 

There  is  a further  use  in  these  connections  of  the  mem- 
branes surrounding  the  great  vessels  with  the  diaphragm,  viz. 
to  preserve  an  equilibrium  or  equal  pressure  upon  the  great 
vessels  of  the  trunk  during  the  violent  action  of  the  muscles. 
Thus  in  leaping,  pulling,  or  straining,  in  any  way,  there  is  a 
sudden  and  great  pressure  on  the  viscera  and  veins  of  the  ab- 
domen, and  at  the  same  time  there  is  a powerful  acceleration 
of  the  blood  from  every  remote  part  towards  the  great  veins 
and  right  sinus  of  the  heart.  These  vessels  would  be  over- 
powered and  burst  but  for  the  protection  of  the  mediastinum, 
and  the  support  which  the  diaphragm  gives  by  its  connection 
with  the  mediastinum,  and  by  acting  in  opposition  to  the  ab- 
dominal muscles. 


VOL.  I. 


D dd 


394 


OF  THE  PERICARDIUM. 


OB  THE  PERICARDIUM. 

The  pericardiuna,  or  heart  purse,  is  the  third  cavity  of  the 
thorax ; but  here  again  I must  caution  my  readers  on  the  use 
of  the  term  cavity.  The  pericardium  closely  embraces  the 
heart,  retains  the  lubricating  fluid,  and  restrains  and  limits  the 
heart’s  motion.  But  this  being  already  explained,  I have 
only  to  add  a circumstance  not  noticed  under  the  former 
head.  The  pericardium  is  a double  membrane : the  inner 
layer  of  membrane  belongs  to  the  class  of  serous  membranes ; 
the  outer  is  quite  of  a different  character,  being  a tissue  of 
strong  fibres  which  form  a web  as  strong  as  a fascia.  It  is  this 
external  layer  of  the  pericardium  which  is  continued  upon 
the  great  vessels  as  they  arise  from  the  heart,  and  which 
forms  their  supporting  sheath  ; and  what  the  closer  texture  of 
the  sheath  does  to  restrain  and  support  the  arteries  and  veins, 
is  done  by  this  outward  layer  of  the  pericardium  to  the 
heart. 

The  next  point  left  unexplained  is  the  manner  in  which  the 
heart  and  pericardium  are  embraced  by  the  pleura. 


In  this  plan  we  see  how  the  heart,  surrounded  by  the  peri- 
cardium, is  further  embraced  by  the  mediastinum,  by  which 
it  is  not  only  supported,  but  the  great  vessels  are  surrounded 
and  led  securely  out  of  the  thorax,  until  they  reach  their  pro- 
per sheaths  in  ascending  upon  the  neck  or  passing  out  into  the 
axilla. 

n The  heart,  h the  pericardium,  cc  the  pleiira  of  ilic  ri^lit  aud  of  the  left,  side, 
embiacingThe  peiitardiura  belwist  them. 


OF  THE  THYMUS  GLAND. 


395 


OF  THE  THYMUS  GLAND. 

The  thymus  is  a gland  of  a pale  colour  and  soft  consistence, 
having  many  divisions  or  lobuli.  It  lies  immersed  in  the  cel- 
lular membrane  of  the  anterior  mediastinum,  but  stretches 
upwards  on  the  neck,  and  its  extremities  are  betwixt  the  tra- 
chea and  carotid  arteries,  but  it  lies  principally  on  the  peri- 
cardium. It  has  two  superior  cornua,  and  two  inferior, 
the  right  of  which  is  the  longest.  On  puncturing  this  gland 
a white  fluid  may  be  expressed,  and  when  we  blow  into  this 
puncture  the  air  pervades  the  whole  gland,  giving  the  appear- 
ance of  a cellular  texture ; but  no  ducts  have  been  disco- 
vered. The  thymus  occupies  a very  considerable  space  in  the 
chest  of  the  foetus,  while  it  diminishes  rapidly  during  child- 
hood ; therefore  it  is  presumed,  that  it  has  a function  adapted 
to  some  peculiarity  of  the  foetal  circulation : but  not  even  a 
probable  conjecture  has  been  offered  further.  It  has  been 
supposed  a kind  of  diverticulum  chyli.  It  has  been  supposed 
to  secrete  a fluid  to  attenuate  the  blood  ; it  has  been  supposed 
to  separate  a peculiar  fluid  which  was  again  thrown  into  the 
blood  through  the  small  veins.  It  has  been  supposed  useful 
to  fill  up  the  thorax  during  the  contracted  state  of  the  lungs 
in  the  foetus ; forgetting  altogether  that  it  is  large  in  the 
foetus  and  diminishes  after  birth,  it  has  been  supposed  to 
protect  the  lungs  from  the  pressure  of  the  sternum  ; all  which 
are  suppositions  merely,  that  have  not  the  most  distant  proof 
to  support  them,  and  yet  possess  not  sufficient  absurdity  to 
make  them  worthy  to  be  recollected  on  that  account. 

OF  THE  LUNGS. 

The  lungs  are  the  soft  compressible  bodies  which  fill  the 
two  lateral  cavities  of  the  chest ; and  their  use  is  to  convey 
the  atmospheric  air  into  contact  with  the  circulating  blood. 
They  consist  principally  of  a cellular  texture,  and  air  tubes 
communicating  with  the  atmosphere  through  the  trachea. 
The  degree  of  fleshy  consistence  and  solidity  which  they 
have,  is  owing  to  the  many  vessels  which  carry  blood  through 
them,  and  the  firm  texture  of  membrane  necessary  to  support 
them.  Their  function  is  respirstion. 

Respiration  carries  away  the  superfluous  carbon  of  the 
blood,  bestows  heat,  and  stimulates  the  system,  endows  ns 


or  THE  TRACHEA  AND  BRONCHI. 

th  the  power  of  speech,  and  affords  us  the  sense  of  smelling, 

' grc  iiiy  contributes  to  the  perfection  of  the  sense, 
in  form,  the  lungs  correspond  to  the  cavity  which  contains 
thiin.  When  taken  from  their  place  and  extended,  they  are 
wide  below,  forming  a base,  and  rise  conicaUy  upward ; con- 
cave where  they  lie  on  the  arch  of  the  diaphragm,  obtuse- 
above,  convex  forward,  and  more  slightly  so  on  the  sides ; the 
borders  of  the  lungs  behind  are  obtuse,  pointed  and  thin  be- 
fore. The  lungs  have  a deep  sulcus  behind  left  for  the  spine, 
and  within  the  projecting  lobes  there  is  a place  of  lodgment- 
for  the  pericardium  and  heart. 

Attending  to  this  general  form,  we  see  why  the  lungs  are 
spoken  of  as  double,  for  unless  by  the  connection  of  their 
common  wind-pipe  there  are  two  great  lateral  portions,  each 
ot  which  belongs  to  a distinct  cavity.  And  when  we  look  to 
the  lungs  of  the  two  sides,  we  discover  that  they  are  not  per- 
fectly alike.  On  each  lung  a fissure  begins  a little  above  the 
apex,  and  runs  obliquely  forward  and  downward  to  the  base., 
This  fissure  on  the  left  side  divides  the  lung  into  two  lobes. 
On  the  right  side  there  is  a lesser  fissure,  which  consequently 
forms  a lesser  intermediate  triangular  lobe. 


OF  THE  TRACHEA  AND  BRONCHI. 

The  trachea  is  that  extent  of  the  wind-pipe  which  is  be- 
twixt the  LARYNX  (already  described)  and  the  division  of  this 
tube  where  it  is  about  to  enter  the  lungs.  It  is  seated  on  the 
forepart  of  the  neck  and  anterior  to  the  oesophagus  or  gullet. 
It  is  covered  by  the  thyroid  gland  and  the  flat  muscles  going 
from  the  sternum  to  the  os  hyoides  and  thyroid  cartilage,  and 
all  around,  it  has  a very  loose  and  elastic  cellular  membrane. 

The  trachea  is  not  a perfect  cylinder,  it  is  flat  on  the  back 
part ; it  is  rigid  to  admit  of  the  easy  passage  of  the  air  through 
It;  and  this  rigidity  is  derived  from  the  cartilaginous  hoops  of 
W 'dch  it  is  principally  formed.  These  are  not  perfectly  re- 
fe’ iar : above  they  are  most  so,  and  are  broader,  and  have 
w r :er  cornua  the  nearer  the  bifurcation  : they  are  united  by 
Hi-  mtermediate  ligamentous  substance,  which  appears  to  be 
;■  :rcuiar ; and  these  cornuae  have  transverse  fibres  uniting 
them,  which  also  appear  to  be  muscular. 

The  membrane  lining  the  trachea,  and  continued  from  the 
larynx  into  the  cells  of  the  lungs  is  as  we  have  already  said  a 
mucous  membrane ; it  is  soft,  elastic,  and  vascular ; many 
pores  of  foramina  open  upon  it,  especially  about  the  larynx 
and  epiglottis.  These  are  the  openings  of  the  ducts  of  glands, 


OF  THE  TRACHEA  AND  BRONCHI. 


397 


and  on  the  outside  of  the  membrane  round  and  oval  glands 
are  visible.  The  moisture  which  bedews  the  trachea  is  a 
limpid  bland  mucus  which  subsides  in  water,  unless  air  bub- 
bles be  in  it.  The  thinner  part  of  this  secretion  is  carried  off 
by  the  air  which  passes  through  the  trachea,  and  the  thick 
matter  is  expectorated. 

This  secretion  which  in  the  healthy  state  is  of  the  con- 
sistence of  thin  jelly,  transparent  and  of  a bluish  colour’,  be- 
comes, from  inflammation  of  the  catarrhal  kind,  thinner  and 
more  transparent,  and  is  copiously  expectorated.  In  more 
chronic  inflammation  the  matter  becomes  thick,  opaque,  and 
of  the  colour  of  straw.  And  in  a still  later  stage  it  may  come 
purulent,  without  implying  lesion  of  surface.  The  firmer 
modules  of  viscid  secretion  which  are  brought  up  are  probably 
from  the  sacculi  laryngis. 

From  its  exposed  situation,  its  sensibility  and  vascularity, 
the  membrane  of  the  trachea  is  very  s’ubject  to  disease.  I 
have  now  before  me  examples  of  general  inflammation,  of  in- 
flammatory crust,  of  suppuration  and  deep  ulcer  in  the  inside 
of  the  trachea.  Often  lesser  degrees  of  inflammation  change 
the  nature  of  the  bland  secretion,  making  it  more  saline, 
acrid,  and  stimulating.  Sometimes  the  inflammatory  action 
will  mix  a portion  of  coagulable  lymph  with  the  mucus  secreted, 
and  which,  by  this  addition,  will  take  a tubular  form,  as  in 
the  croup.  But  let  it  be  remembered,  that  coagulable  lymph, 
in  the  form  of  tubes  or  vessels  may  be  coughed  up  from  the 
lungs,  a consequence  of  blood  poured  into  the  bronchi  with- 
out the  presence  of  inflammation. 

On  entering  the  thorax  the  trachea  inclines  backward,  and 
passes  into  the  posterior  mediastinum,  and  behind  the  arch  of 
the  aorta  and  before  the  cesophagus ; opposite  to  the  third 
vertebrae  of  the  back  it  divides  into  two  branches,  passing  to 
the  right  and  left;  these  and  their  subdivisions  are  the 
bronchi. 

When  we  follow  one  of  these  tubes  we  find  it  entering  the 
substance  of  the  lungs,  accompanied  by  blood-vessels,  branches 
of  the  pulmonary  artery,  with  their  corresponding  veins ; and 
lesser  arterial  branches  enter  here,  which  are  derived  from  the 
aorta,  and  are  called  the  bronchial  arteries. 

The  bronchi  divide  and  subdivide  in  regular  order,  branch- 
ing like  a tree  through  all  the  substance  of  the  lungs,  until 
their  tender  extremities  terminate  in  their  air  cells ; for  the 
cartilaginous  rings  of  the  bronchi  which  near  the  trachea  re- 
semble those  of  the  trunk,  become  weaker  and  further  re- 
moved from  each  other,  until  the  extremities  seem  only  to  be 
membranous  tubes. 


398 


OF  THE  BRONCHIAL  CELLS. 


BKONCHIAL  CELLS. 

The  BRONCHIAL  CELLS,  into  which  the  air  is  admitted  in 
respiration,  have  been  represented  as  very  regular  sphericles 
attached  to  the  branches  of  the  bronchi,  and  having  no  com- 
munication with  each  other.  I rather  believe  that  they  are 
not  regular  in  figure  nor  in  size,  and  that  they  freely  commu- 
nicate. Perhaps  I am  mistaken  in  supposing  I see  that  the 
cells  not  only  communicate,  but  that  the  air  is  drawn  through 
them,  and  made  to  circulate  among  them  in  a series.  Taking 
this  as  a question  to  be  judged  of  more  by  the  probable  effect 
of  the  structure,  than  by  what  we  can  demonstrate,  would 
not  the  air,  in  the  supposition  of  its  being  drawn  through  the 
communications  from  cell  to  cell,  in  connection  with  the  ex- 
tremity of  a branch  of  the  bronchus,  be  more  effectually 
brought  into  contact  with  the  blood,  than  if  the  extreme 
branch  of  the  wind-pipe  terminated  in  a cell  which  had  one 
opening  only,  and  which  cell  contracted  during  expiration, 
only  in  a slight  degree.? 

On  these  cells  the  ultimate  branches  of  the  pulmonary  arte- 
ries and  veins  ramify  and  inosculate,  and  the  thin  membrane 
of  the  cell  and  the  coats  of  these  minute  vessels  do  not  pre- 
vent the  influence  of  the  air  upon  the  circulating  blood.  My 
reader  must  well  distinguish  betwixt  this  regular  cellular 
structure,  for  the  admission  of  air  which  is  drawn  through  the 
trachea  and  bronchi,  and  that  cellular  texture  of  the  lungs 
which  is  common  to  them  and  every  part  of  the  body  ; a tissue 
which  supports  the  air-cells,  the  bronchi,  and  the  three 
several  kinds  of  blood-vessels,  and  the  lymphatics  which  col- 
lectively constitute  the  substance  of  the  lungs.  This  common 
cellular  substance  supports  the  air-cells,  and  unites  the  lobules, 
and  conveys  the  vessels  to  their  destination. 

Sometimes  the  air  escapes  from  the  proper  bronchial  cells 
into  thin  cellular  texture;  then  there  is  emphysema  of  the 
lungs  ; then  the  lungs  are  distended  with  air ; but  that  air  does 
not  minister  to  the  oxygenation  of  the  blood,  on  the  con- 
trary, the  patient  dies  suffocated.  And  still  more  frequently 
it  happens  that  the  lungs  being  exerted  as  byi  difficult  respi- 
ration, a watery  effusion  takes  place  in  the  common  cellular 
texture  of  the  lungs,  which  effectually  compresses  the  proper 
air  cells,  and  after  much  oppression  suffocates. 


OF  THE  BLOOD  IN  THE  LUNGS. 


399 


COURSE  OF  THE  BLOOD  IN  THE  LUNGS. 

Coloured  water,  or  size,  or  oil  of  turpentine,  being  injected 
into  the  pulmonary  artery,  returns  by  the  pulmonic  veins,  run- 
ning in  what  is  called  the  lesser  circulation.  The  same  fluids 
being  injected  into  the  vein,  return  by  the  artery.*  The  fluid 
being  more  forcibly  propelled  into  the  pulmonary  artery, 
flows  by  the  trachea,  and  the  exudation  of  the  fluid  is  facilita- 
ted, if  the  action  of  respiration  be  imitated  by  blowing  into  the 
trachea  at  the  time  of  the  injection.  These  coarse  experi- 
ments in  the  dead  body  prove  little ; but  the  course  of  the 
blood  from  the  extreme  pulmonic  arteries  into  the  veins,  hav- 
ing been  seen  in  the  rnembranous  lungs  of  the  lacertfe,  the 
chemical  phenomena  exhibited  by  respiration,  leave  little  for 
us  to  wish  further  in  explanation  of  the  functions  of  the  lungs.f 

There  are  some  reflections  which  naturally  occur  in  taking 
leave  of  this  subject  of  respiration,  which  may  have  the  fur- 
ther efiect  of  confirming  in  my^  reader  the  accurate  knowledge 
of  the  anatomy. 

Although  the  lungs  are  very  often  found  adhering  to  the  in- 
side of  the  chest,  and  although  this  union  occurs  where  we 
cannot  discover  that  the  person  during  life  was  subject  to  any 
inflammation  of  the  chest,  yet  it  is  a preternatural  appearance. 
The  lungs. (covered  with  the  pleura)  lie  in  contact  with  the 
sides  of  the  chest,  and  consequently  with  the  pluera  costalis, 
but  without  adhesion.  They  are  passive  in  the  motion  of  res- 
piration. The  muscles  of  respiration  clothing  the  thorax  are 
the  agents  in  this  function.  The  bony  and  cartilaginous  tex- 
ture of  the  thorax  in  the  machinery  put  in  motion,  and  the  ef- 
fect is  the  dilatation  of  the  lungs ; for  as  the  sides  of  the  chest 
rise,  the  lungs  being  in  close  contact,  they  must  follow  this  ris- 
ing, and  as  the  dilatation  of  the  lungs  is  freely  permitted  by  the 
entrance  of  the  atmosphere  through  the  trachea  into  their 
cells,  the  effect  of  the  action  of  the  muscles  of  inspiration  is  the 
drawing  of  the  atmospheric  air  into  the  bronchial  cells,  and 
the  contact  of  that  air  with  the  blood  circulating  in  the  lungs. 
In  expiration  the  lungs  are  equally  passive  as  in  inspiration. 
The  muscles  which  contract  the  diameters  of  the  thorax,  force 
the  compages  of  bones  and  cartilages  upon  the  lungs,  and  com- 
pressing them,  throw  out  the  air  by  the  trachea. 

* In  an  experiment  which  was  made  this  season  by  a pupil  of  mine,  the  mercury,  wliich 
■was  thrown  into  the  veins  of  a live  ass,  was  found  at  the  end  of  a month  to  be  lodged  in  the 
cells  of  the  lungs : it  had  not  been  forced  into  the  pulmonary  veins. 

t For  the  consent  or  sympathy  of  the  lungs  with  othei-  part?,  see  the  observations  under 
the  head  oi  Par^vag^m,  in  the  description  of  the  nerves. 


400 


OF  THE  BLOOD  IN  THE  LUNGS, 


That  any  other  idea  should  arise  in  the  student’s  mind  is 
owing  to  two  circumstances ; first,  the  not  comprehending  the 
principles  of  natural  philosophy,  and  puzzling  himself  with  the 
expression  that  the  air  fills  the  lungs  by  its  weight ; which  is 
true,  but  it  is  as  true  that  the  milk  enters  the  mouth  of  a suck- 
ing infant  by  the  weight  of  the  atmosphere,  or  that  in  using  a 
syringe,  it  is  the  weight  of  air  which  forces  the  fluid  into  the 
syringe.  The  air  enters  the  lungs  by  suction ; the  motion 
of  the  thoi’ax  produces  that  suction ; or,  in  other  words,  the 
operation  of  the  weight  of  the  air  is  permitted  to  take  effect 
by  the  tendency  to  a vacuum  which  the  rising  of  the  sides  of 
the  thorax  produces ; the  pressure  of  the  atmosphere  then 
causes  the  air  to  descend  into  the  bronchial  cells. 

The  second  circumstance  which  gives  occasion  to  miscon- 
conception,  is  the  lungs  seeming  to  have  a motion  independent 
of  the  chest. 

Thus  when  a man  is  wounded  betwixt  the  ribs,  the  lungs 
protrude,  and  this  rising  of  the  lungs  appears  to  be  owing  to 
a power  inherent  in  them  ; but  attention  to  the  true  circum- 
stance will  explain  the  occasion  of  this.  When  the  wound  is 
received,  the  air  enters  the  chest,  and  the  lungs  fall  collapsed, 
the  cavity  is  therefore  full  of  air,  and  the  lobes  of  the  lungs 
hang  loose.  The  air  plays  freely  out  and  in  through  the  hole 
in  the  chest.  But  when  by  change  of  posture  the  flapping 
edge  of  the  lungs  fall  against  the  hole  in  the  side,  the  air 
which  is  in  the  chest  can  no  longer  make  its  exit,  without 
forcing  the  lungs  through  the  wound.  Accordingly,  in  the  act 
of  expiration,  the  same  compression  which 'forces  the  air  out 
in  breathing  pushes  out  the  lungs  from  the  side.  We  may 
have  the  proof  from  anatomy  that  the  lungs  lie  in  close  con- 
tact with  the  pleura  costalis. 

When  the  intercostal  muscles  are  dissected  off*,  and  the  pleu- 
ra costalis  exposed,  the  surface  of  the  lungs  is  seen  in  contact 
with  that  transparent  membrane,  and  when  the  pleura  is  punc- 
tured with  the  lancet,  the  air  rushes  in,  and  visibly  the  lungs 
retire  in  proportion  as  the  air  is  admitted.  This  proximity  of 
the  lungs  to  the  ribs  explains  the  effect  of  fracture  of  these 
bones  in  producing  the  tumour  called  emphysema,  for  thus  it 
happens.  The  broken  end  of  the  rib  piercing  tbe  pleura  cos- 
talis, tears  also  the  pleura  pulmonalis,  and  breaks  the  surface 
of  the  lungs,  and  opens  the  bronchial  cells.  Now  when  the 
chest  is  expanded,  a little  air  is  drawn  through  the  rugged 
opening,  and  lodges  in  the  cavity  of  the  chest,  (now  truly  a 
cavity,  the  air  occupying  the  space  betwixt  tbe  lungs  and 
chest.)  By  little  and  little  the  small  portion  of  air  which  is 
drawn  into  the  cavity  of  the  chest  at  each  inspiration  accumu- 


Firet  plan  exhibits  a section  of  the  thorax,  with  the  rib  broken,  and  entering  the  lungs  A. 
Air  has  already  begun  to  accumulate  in  the  cavity  of  the  chest  B.  The  air  insinuating  itself 
by  the  side  of  the  broken  rib  forms  the  tumour  on  the  side  C.  The  second  plan  exhibits  the 
extent  of  the  evil.  The  lungs  D are  compressed.  The  cavity  of  the  chest  left  by  the  retrac- 
tion of  the  lungs  is  full  of  air.  The  emphysematous  tumour  E is  extended  over  the  body. 
The  right  side  of  the  diaphragm  E is  pushed  down,  the  heart  and  mediastinum  F is  forced 
towards  the  opposite  side,  encroaching  on  the  lungs  of  the  left  side. 


OF  THE  BLOOD  IN  THE  LUNGS.  401 


lates  until  a distressing  quantity  fills  the  whole  of  that  side  of 
the  chest. 

The  chest  being  now  full  of  air,  the  action  of  expiration, 
compressing  the  air  in  the  chest,  it  insinuates  itself  by  the  ^de 
of  the.  fractured  ribs  into  the  cellular  texture,  consequently  a 
crepitating  tumour  of  air  is  formed  over  the  part  hurt,  and  this 
quickly  extends  over  the  whole  body,  until  the  skin  is  blown 
up  like  a sac  ! and  the  man  is  in  danger  of  suffocation.  The 
suffocation  is  not  a consequence  of  this  distention  of  the  cel- 
lular substance  of  the  body,  but  of  the  fulness  of  the  cavity  of 
the  chest  on  that  side  wounded.  For,  at  length,  the  chest  being 
kept  distended,  and  the  diaphragna  pushed  down,  and  the  me- 
diastinum passed  to  the  opposite  side,  both  sides  of  the  chest 
are  oppressed,  and  the  breathing  is  so  checked,  that  if  not 
quickly  relieved  the  patient  would  die. 


These  plans  will  explain  the  common  case  of  emphysema  : 


VOL,  I. 


E e e 


402  OF  THE  BLOOD  IN  THE  LUNGS. 

The  emphysema  of  the  body  may  take  place  in  a different 
way.  The  lungs  may  be  diseased  ; air  may  be  drawn  through 
the  abscess,  and  collect  in  the  cavity  of  the  chest ; or  the 
bronchial  and  true  air  cells  may  be  hurt  by  exertion,  so  that 
the  air  gets  access  into  the  common  cellular  texture  of  the 
lungs  ; and  from  the  lungs  it  may  find  its  way  betwixt  the  liga- 
ments of  the  lungs  into  the  cellular  texture  of  the  mediasti- 
num, and  hence  up  into  the  neck  and  over  the  body.  These 
last  instances  are  rare  compared  with  that  proceeding  from 
fractured  rib. 


END  Of  the  first  volume. 


I 


